Index: openacs-4/packages/acs-admin/www/apm/version-dependencies.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-admin/www/apm/version-dependencies.tcl,v
diff -u -N -r1.5 -r1.6
--- openacs-4/packages/acs-admin/www/apm/version-dependencies.tcl	5 Jan 2010 01:34:54 -0000	1.5
+++ openacs-4/packages/acs-admin/www/apm/version-dependencies.tcl	10 Mar 2010 00:44:03 -0000	1.6
@@ -13,7 +13,7 @@
 
 "
 
-foreach dependency_type { provide extend require } {
+foreach dependency_type { provide require extend embed } {
 
     set dependency_type_prep "${dependency_type}s"
     if { [string index $dependency_type end] eq "e" } {
@@ -38,7 +38,7 @@
 	set sign [ad_decode $dependency_type "provide" "<=" ">="]
 
 	set counter 0
-        set other_dependency_in [ad_decode $dependency_type "provide" "'requires','extends'" "'provides'"]
+        set other_dependency_in [ad_decode $dependency_type "provide" "'requires','extends','embeds'" "'provides'"]
 	db_foreach apm_specific_version_dependencies {} {
             incr counter
 	    if { $counter == 1 } {
@@ -48,6 +48,7 @@
                 provides { set dep_d provided }
                 requires { set dep_d required }
                 extends { set dep_d extended }
+                embeds { set dep_d embeds }
             } 
 	    doc_body_append "<li>[string totitle $dep_d] by <a href=\"version-view?version_id=$dep_version_id\">$dep_pretty_name, version $dep_version_name</a>\n"
 	}
Index: openacs-4/packages/acs-admin/www/apm/version-dependency-add-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-admin/www/apm/version-dependency-add-2.tcl,v
diff -u -N -r1.9 -r1.10
--- openacs-4/packages/acs-admin/www/apm/version-dependency-add-2.tcl	28 Feb 2010 02:22:34 -0000	1.9
+++ openacs-4/packages/acs-admin/www/apm/version-dependency-add-2.tcl	10 Mar 2010 00:44:03 -0000	1.10
@@ -30,8 +30,14 @@
             apm_copy_inherited_params $our_package_key
 	}
 
+        embed {
+	    apm_dependency_add -dependency_id $dependency_id ${dependency_type}s $version_id $package_key $version_name
+            apm_build_one_package_relationships $our_package_key
+            apm_copy_inherited_params $our_package_key
+	}
+
 	default {
-	    ad_return_complaint 1 "Entry error: Depenendencies are either provided or required."
+	    ad_return_complaint 1 "Entry error: Allowable dependencies are required, extends and embeds."
 	}
     }
 } on_error {
Index: openacs-4/packages/acs-kernel/acs-kernel.info
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/acs-kernel.info,v
diff -u -N -r1.109 -r1.110
--- openacs-4/packages/acs-kernel/acs-kernel.info	5 Mar 2010 12:22:07 -0000	1.109
+++ openacs-4/packages/acs-kernel/acs-kernel.info	10 Mar 2010 00:44:03 -0000	1.110
@@ -7,15 +7,15 @@
     <initial-install-p>t</initial-install-p>
     <singleton-p>t</singleton-p>
     
-    <version name="5.6.0d5" url="http://openacs.org/repository/download/apm/acs-kernel-5.6.0d5.apm">
+    <version name="5.6.0d6" url="http://openacs.org/repository/download/apm/acs-kernel-5.6.0d6.apm">
         <owner url="mailto:oct@openacs.org">OpenACS Core Team</owner>
         <summary>Routines and data models providing the foundation for OpenACS-based Web services.</summary>
         <release-date>2009-06-19</release-date>
         <vendor url="http://openacs.org">OpenACS</vendor>
         <description format="text/html">The OpenACS kernel contains the core datamodel create and drop scripts for such things as objects, groups, partiies and the supporting PL/SQL and PL/pgSQL procedures.</description>
         <maturity>3</maturity>
 
-        <provides url="acs-kernel" version="5.6.0d5"/>
+        <provides url="acs-kernel" version="5.6.0d6"/>
 
         <callbacks>
         </callbacks>
Index: openacs-4/packages/acs-kernel/sql/oracle/apm-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/oracle/apm-create.sql,v
diff -u -N -r1.45 -r1.46
--- openacs-4/packages/acs-kernel/sql/oracle/apm-create.sql	20 Jan 2010 00:17:17 -0000	1.45
+++ openacs-4/packages/acs-kernel/sql/oracle/apm-create.sql	10 Mar 2010 00:44:03 -0000	1.46
@@ -562,6 +562,10 @@
 			        references apm_package_types (package_key),
 	parameter_name		varchar2(100) 
 				constraint apm_pack_params_name_nn not null,
+        scope                   varchar2(20) default 'instance'
+                                constraint apm_parameters_scope_ck
+                                check (scope in ('global','instance'))
+                                constraint apm_parameters_scope_nn not null,
         description		varchar2(2000),
 	section_name		varchar2(200),
 	datatype	        varchar2(100) 
@@ -595,6 +599,11 @@
   This is the name of the parameter, for example "DebugP."
 ';
 
+comment on column apm_parameters.scope is '
+  If the scope is "global", only one value of the parameter exists for the entire site.
+  If "instance", each package instance has its own value.
+';
+
 comment on column apm_parameters.description is '
   A human readable description of what the parameter is used for.
 ';
@@ -764,7 +773,7 @@
     dependency_type    varchar2(20)
                        constraint apm_package_deps_type_nn not null
                        constraint apm_package_deps_type_ck
-                       check(dependency_type in ('extends', 'provides','requires')),
+                       check(dependency_type in ('embeds', 'extends', 'provides','requires')),
     service_uri        varchar2(1500)
                        constraint apm_package_deps_uri_nn not null,
     service_version    varchar2(100)
@@ -1044,11 +1053,6 @@
 			default null
   ) return apm_packages.package_id%TYPE;
 
-function is_child(
-  parent_package_key in apm_package_dependencies.service_uri%TYPE,
-  child_package_key in apm_package_dependencies.service_uri%TYPE
-) return integer;
-
   procedure del (
    package_id		in apm_packages.package_id%TYPE
   );
@@ -1844,36 +1848,7 @@
 
   end if;
 end new;
-
-function is_child(
-  parent_package_key in apm_package_dependencies.service_uri%TYPE,
-  child_package_key in apm_package_dependencies.service_uri%TYPE
-) return integer
-is 
-  cursor dependencies is
-  select apd.service_uri
-  from apm_package_versions apv, apm_package_dependencies apd
-  where apd.version_id = apv.version_id
-    and apv.enabled_p = 't'
-    and apd.dependency_type = 'extends'
-    and apv.package_key = child_package_key;
-begin
-
-  if parent_package_key = child_package_key then
-    return 1;
-  end if;
-
-  for dependency in dependencies loop
-    if dependency.service_uri = parent_package_key or
-      apm_package.is_child(parent_package_key, dependency.service_uri) = 1 then
-      return 1;
-    end if;
-  end loop;
-      
-  return 0;
-
-end;
-
+  
   procedure del (
    package_id		in apm_packages.package_id%TYPE
   )
Index: openacs-4/packages/acs-kernel/sql/postgresql/acs-metadata-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/acs-metadata-create.sql,v
diff -u -N -r1.29 -r1.30
--- openacs-4/packages/acs-kernel/sql/postgresql/acs-metadata-create.sql	26 Jun 2009 00:38:33 -0000	1.29
+++ openacs-4/packages/acs-kernel/sql/postgresql/acs-metadata-create.sql	10 Mar 2010 00:44:03 -0000	1.30
@@ -61,7 +61,7 @@
   return tree_sortkey from acs_object_types where object_type = p_object_type;
 end;' language 'plpgsql';
 
-create function acs_object_type_insert_tr () returns opaque as '
+create function acs_object_type_insert_tr () returns trigger as '
 declare
         v_parent_sk     varbit default null;
         v_max_value     integer;
@@ -84,7 +84,7 @@
 on acs_object_types for each row 
 execute procedure acs_object_type_insert_tr ();
 
-create function acs_object_type_update_tr () returns opaque as '
+create function acs_object_type_update_tr () returns trigger as '
 declare
         v_parent_sk     varbit default null;
         v_max_value     integer;
Index: openacs-4/packages/acs-kernel/sql/postgresql/acs-objects-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/acs-objects-create.sql,v
diff -u -N -r1.60 -r1.61
--- openacs-4/packages/acs-kernel/sql/postgresql/acs-objects-create.sql	16 Jul 2009 00:40:07 -0000	1.60
+++ openacs-4/packages/acs-kernel/sql/postgresql/acs-objects-create.sql	10 Mar 2010 00:44:03 -0000	1.61
@@ -258,7 +258,7 @@
 
 create index acs_objects_object_type_idx on acs_objects (object_type);
 
-create function acs_objects_mod_ip_insert_tr () returns opaque as '
+create function acs_objects_mod_ip_insert_tr () returns trigger as '
 begin
   new.modifying_ip := new.creation_ip;
 
@@ -271,7 +271,7 @@
 
 -- show errors
 
-create function acs_objects_last_mod_update_tr () returns opaque as '
+create function acs_objects_last_mod_update_tr () returns trigger as '
 begin
   if new.last_modified is null then
      new.last_modified := old.last_modified;
@@ -293,7 +293,7 @@
   return tree_sortkey from acs_objects where object_id = p_object_id;
 end;' language 'plpgsql' stable strict;
 
-create function acs_objects_insert_tr() returns opaque as '
+create function acs_objects_insert_tr() returns trigger as '
 declare
         v_parent_sk    		varbit default null;
         v_max_child_sortkey	varbit;
@@ -323,7 +323,7 @@
 execute procedure acs_objects_insert_tr ();
 
 
-create function acs_objects_update_tr () returns opaque as '
+create function acs_objects_update_tr () returns trigger as '
 declare
         v_parent_sk     varbit default null;
         v_max_child_sortkey	varbit;
@@ -438,7 +438,7 @@
    from acs_object_context_index
    where object_id != ancestor_id;
 
-create or replace function acs_objects_context_id_in_tr () returns opaque as '
+create or replace function acs_objects_context_id_in_tr () returns trigger as '
 declare
         security_context_root integer;
 begin
@@ -472,7 +472,7 @@
 create trigger acs_objects_context_id_in_tr after insert on acs_objects
 for each row execute procedure acs_objects_context_id_in_tr ();
 
-create or replace function acs_objects_context_id_up_tr () returns opaque as '
+create or replace function acs_objects_context_id_up_tr () returns trigger as '
 declare
         pair    record;
         outer record;
@@ -544,7 +544,7 @@
 create trigger acs_objects_context_id_up_tr after update on acs_objects
 for each row execute procedure acs_objects_context_id_up_tr ();
 
-create function acs_objects_context_id_del_tr () returns opaque as '
+create function acs_objects_context_id_del_tr () returns trigger as '
 begin
   delete from acs_object_context_index
   where object_id = old.object_id;
Index: openacs-4/packages/acs-kernel/sql/postgresql/acs-permissions-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/acs-permissions-create.sql,v
diff -u -N -r1.33 -r1.34
--- openacs-4/packages/acs-kernel/sql/postgresql/acs-permissions-create.sql	13 Feb 2009 13:36:02 -0000	1.33
+++ openacs-4/packages/acs-kernel/sql/postgresql/acs-permissions-create.sql	10 Mar 2010 00:44:03 -0000	1.34
@@ -118,7 +118,7 @@
 -- This would be better, since the same query could be used for both oracle
 -- and postgresql.
 
-create or replace function acs_priv_hier_ins_del_tr () returns opaque as '
+create or replace function acs_priv_hier_ins_del_tr () returns trigger as '
 declare
         new_value       integer;
         new_key         varbit default null;
@@ -190,7 +190,7 @@
 on acs_privilege_hierarchy for each row
 execute procedure acs_priv_hier_ins_del_tr ();
 
-create or replace function acs_priv_del_tr () returns opaque as '
+create or replace function acs_priv_del_tr () returns trigger as '
 begin
 
   delete from acs_privilege_descendant_map
@@ -418,7 +418,7 @@
        lck  integer
 );
 
-create function acs_permissions_lock_tr () returns opaque as '
+create function acs_permissions_lock_tr () returns trigger as '
 begin
         raise EXCEPTION ''FOR LOCKING ONLY, NO DML STATEMENTS ALLOWED'';
         return null;
Index: openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql,v
diff -u -N -r1.30 -r1.31
--- openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql	6 Jan 2010 20:07:24 -0000	1.30
+++ openacs-4/packages/acs-kernel/sql/postgresql/acs-relationships-create.sql	10 Mar 2010 00:44:03 -0000	1.31
@@ -394,7 +394,7 @@
 
 -- added by oumi@arsdigita.com - Jan 11, 2001
 
-create function acs_rels_in_tr () returns opaque as '
+create function acs_rels_in_tr () returns trigger as '
 declare
   dummy integer;
   target_object_type_one acs_object_types.object_type%TYPE;
Index: openacs-4/packages/acs-kernel/sql/postgresql/apm-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/apm-create.sql,v
diff -u -N -r1.69 -r1.70
--- openacs-4/packages/acs-kernel/sql/postgresql/apm-create.sql	29 Dec 2008 21:02:29 -0000	1.69
+++ openacs-4/packages/acs-kernel/sql/postgresql/apm-create.sql	10 Mar 2010 00:44:03 -0000	1.70
@@ -708,6 +708,11 @@
 	datatype	        varchar(100) not null
 			        constraint apm_parameters_datatype_ck 
 				check(datatype in ('number', 'string','text')),
+        scope                   varchar(10) default 'instance'
+                                constraint apm_parameters_scope_ck
+                                check (scope in ('global','instance'))
+                                constraint apm_parameters_scope_nn
+                                not null,
 	default_value		text,
 	min_n_values		integer default 1 not null
 			        constraint apm_parameters_min_n_values_ck
@@ -733,6 +738,11 @@
   This is the name of the parameter, for example "DebugP."
 ';
 
+comment on column apm_parameters.scope is '
+  If the scope is "global", only one value of the parameter exists for the entire site.
+  If "instance", each package instance has its own value.
+';
+
 comment on column apm_parameters.description is '
   A human readable description of what the parameter is used for.
 ';
@@ -837,6 +847,22 @@
    ''f''
    );
 
+attr_id := acs_attribute__create_attribute (
+   ''apm_parameter'',
+   ''scope'',
+   ''string'',
+   ''Scope'',
+   ''Scope'',
+   null,
+   null,
+   null,
+   1,
+   1,
+   null,
+   ''type_specific'',
+   ''f''
+   ); 
+
  attr_id := acs_attribute__create_attribute (
    ''apm_parameter'',
    ''datatype'',
@@ -996,7 +1022,7 @@
     dependency_type    varchar(20)
                        constraint apm_package_deps_type_nn not null
                        constraint apm_package_deps_type_ck
-                       check(dependency_type in ('extends', 'provides','requires')),
+                       check(dependency_type in ('embeds', 'extends', 'provides','requires')),
     service_uri        varchar(1500)
                        constraint apm_package_deps_uri_nn not null,
     service_version    varchar(100)
@@ -1307,18 +1333,19 @@
    return 0; 
 end;' language 'plpgsql';
 
-create or replace function apm__register_parameter (integer,varchar,varchar,varchar,varchar,varchar,varchar,integer,integer)
+create or replace function apm__register_parameter (integer,varchar,varchar,varchar,varchar,varchar,varchar,varchar,integer,integer)
 returns integer as '
 declare
   register_parameter__parameter_id           alias for $1;  -- default null  
   register_parameter__package_key            alias for $2;  
   register_parameter__parameter_name         alias for $3;  
-  register_parameter__description            alias for $4;  -- default null  
-  register_parameter__datatype               alias for $5;  -- default ''string''  
-  register_parameter__default_value          alias for $6;  -- default null  
-  register_parameter__section_name           alias for $7;  -- default null 
-  register_parameter__min_n_values           alias for $8;  -- default 1
-  register_parameter__max_n_values           alias for $9;  -- default 1
+  register_parameter__scope                  alias for $4;  
+  register_parameter__description            alias for $5;  -- default null  
+  register_parameter__datatype               alias for $6;  -- default ''string''  
+  register_parameter__default_value          alias for $7;  -- default null  
+  register_parameter__section_name           alias for $8;  -- default null 
+  register_parameter__min_n_values           alias for $9;  -- default 1
+  register_parameter__max_n_values           alias for $10;  -- default 1
 
   v_parameter_id         apm_parameters.parameter_id%TYPE;
   v_value_id             apm_parameter_values.value_id%TYPE;
@@ -1339,10 +1366,10 @@
     );
     
     insert into apm_parameters 
-    (parameter_id, parameter_name, description, package_key, datatype, 
+    (parameter_id, parameter_name, scope, description, package_key, datatype, 
     default_value, section_name, min_n_values, max_n_values)
     values
-    (v_parameter_id, register_parameter__parameter_name, 
+    (v_parameter_id, register_parameter__parameter_name, register_parameter__scope,
      register_parameter__description, register_parameter__package_key, 
      register_parameter__datatype, register_parameter__default_value, 
      register_parameter__section_name, register_parameter__min_n_values, 
@@ -1366,6 +1393,30 @@
    
 end;' language 'plpgsql';
 
+-- For backwards compatibility, register a parameter with "instance" scope.
+
+create or replace function apm__register_parameter (integer,varchar,varchar,varchar,varchar,varchar,varchar,integer,integer)
+returns integer as '
+declare
+  register_parameter__parameter_id           alias for $1;  -- default null  
+  register_parameter__package_key            alias for $2;  
+  register_parameter__parameter_name         alias for $3;  
+  register_parameter__description            alias for $4;  -- default null  
+  register_parameter__datatype               alias for $5;  -- default ''string''  
+  register_parameter__default_value          alias for $6;  -- default null  
+  register_parameter__section_name           alias for $7;  -- default null 
+  register_parameter__min_n_values           alias for $8;  -- default 1
+  register_parameter__max_n_values           alias for $9;  -- default 1
+
+begin
+  return
+    apm__register_parameter(register_parameter__parameter_id, register_parameter__package_key,
+                           register_parameter__parameter_name, ''instance'',
+                           register_parameter__description, register_parameter__datatype,
+                           register_parameter__default_value, register_parameter__section_name,
+                           register_parameter__min_n_values, register_parameter__max_n_values);
+end;' language 'plpgsql';
+
 -- function update_parameter
 create or replace function apm__update_parameter (integer,varchar,varchar,varchar,varchar,varchar,integer,integer)
 returns varchar as '
@@ -1468,40 +1519,99 @@
    
 end;' language 'plpgsql' stable strict;
 
+create or replace function apm__id_for_name (integer,varchar)
+returns integer as '
+declare
+  id_for_name__package_id             alias for $1;  
+  id_for_name__parameter_name         alias for $2;  
+  a_parameter_id                      apm_parameters.parameter_id%TYPE;
+begin
+    select parameter_id into a_parameter_id 
+    from apm_parameters 
+    where parameter_name = id_for_name__parameter_name
+      and package_key = (select package_key from apm_packages
+                         where package_id = id_for_name__package_id);
 
--- function get_value
+    if NOT FOUND
+      then
+      	raise EXCEPTION ''-20000: The specified package % AND/OR parameter % do not exist in the system'', id_for_name__package_id, id_for_name__parameter_name;
+    end if;
+
+    return a_parameter_id;
+   
+end;' language 'plpgsql' stable strict;
+
+create or replace function apm__id_for_name (varchar,varchar)
+returns integer as '
+declare
+  id_for_name__package_key            alias for $1;  
+  id_for_name__parameter_name         alias for $2;  
+  a_parameter_id                      apm_parameters.parameter_id%TYPE;
+begin
+    select parameter_id into a_parameter_id
+    from apm_parameters p
+    where p.parameter_name = id_for_name__parameter_name and
+          p.package_key = id_for_name__package_key;
+
+    if NOT FOUND
+      then
+      	raise EXCEPTION ''-20000: The specified package % AND/OR parameter % do not exist in the system'', id_for_name__package_key, id_for_name__parameter_name;
+    end if;
+
+    return a_parameter_id;
+   
+end;' language 'plpgsql' stable strict;
+
 create or replace function apm__get_value (integer,varchar)
 returns varchar as '
 declare
   get_value__package_id             alias for $1;  
   get_value__parameter_name         alias for $2;  
   v_parameter_id                    apm_parameter_values.parameter_id%TYPE;
+  value                             apm_parameter_values.attr_value%TYPE;
 begin
-    select parameter_id into v_parameter_id 
-    from apm_parameters 
-    where parameter_name = get_value__parameter_name
-    and package_key = (select package_key  from apm_packages
-			where package_id = get_value__package_id);
-    return apm__get_value(
-	v_parameter_id,
-	get_value__package_id
-    );	
+    v_parameter_id := apm__id_for_name (get_value__package_id, get_value__parameter_name);
+
+    select attr_value into value from apm_parameter_values v
+    where v.package_id = get_value__package_id
+    and parameter_id = get_value__parameter_id;
+
+    return value;
    
 end;' language 'plpgsql' stable strict;
 
+create or replace function apm__get_value (varchar,varchar)
+returns varchar as '
+declare
+  get_value__package_key            alias for $1;  
+  get_value__parameter_name         alias for $2;  
+  v_parameter_id                    apm_parameter_values.parameter_id%TYPE;
+  value                             apm_parameter_values.attr_value%TYPE;
+begin
+    v_parameter_id := apm__id_for_name (get_value__package_key, get_value__parameter_name);
 
--- procedure set_value
-create or replace function apm__set_value (integer,integer,varchar)
+    select attr_value into value from apm_parameter_values v
+    where v.package_id is null
+    and parameter_id = get_value__parameter_id;
+
+    return value;
+   
+end;' language 'plpgsql' stable strict;
+
+create or replace function apm__set_value (integer,varchar,varchar)
 returns integer as '
 declare
-  set_value__parameter_id           alias for $1;  
-  set_value__package_id             alias for $2;  
+  set_value__package_id             alias for $1;  
+  set_value__parameter_name         alias for $2;  
   set_value__attr_value             alias for $3;  
+  v_parameter_id                    apm_parameter_values.parameter_id%TYPE;
   v_value_id                        apm_parameter_values.value_id%TYPE;
 begin
+    v_parameter_id := apm__id_for_name (set_value__package_id, set_value__parameter_name);
+
     -- Determine if the value exists
     select value_id into v_value_id from apm_parameter_values 
-     where parameter_id = set_value__parameter_id 
+     where parameter_id = v_parameter_id 
      and package_id = set_value__package_id;
     update apm_parameter_values set attr_value = set_value__attr_value
      where value_id = v_value_id;
@@ -1513,51 +1623,47 @@
          v_value_id := apm_parameter_value__new(
             null,
             set_value__package_id,
-            set_value__parameter_id,
+            v_parameter_id,
             set_value__attr_value
          );
      end if;
 
-     return 0; 
+    return 0; 
 end;' language 'plpgsql';
 
-
--- procedure set_value
-create or replace function apm__set_value (integer,varchar,varchar)
+create or replace function apm__set_value (varchar,varchar,varchar)
 returns integer as '
 declare
-  set_value__package_id             alias for $1;  
+  set_value__package_key            alias for $1;  
   set_value__parameter_name         alias for $2;  
   set_value__attr_value             alias for $3;  
   v_parameter_id                    apm_parameter_values.parameter_id%TYPE;
+  v_value_id                        apm_parameter_values.value_id%TYPE;
 begin
-    select parameter_id into v_parameter_id 
-    from apm_parameters 
-    where parameter_name = set_value__parameter_name
-    and package_key = (select package_key  from apm_packages
-			where package_id = set_value__package_id);
+    v_parameter_id := apm__id_for_name (set_value__package_key, set_value__parameter_name);
 
-    if NOT FOUND
-      then
-      	raise EXCEPTION ''-20000: The specified package % AND/OR parameter % do not exist in the system'', set_value__package_id, set_value__parameter_name;
-    end if;
+    -- Determine if the value exists
+    select value_id into v_value_id from apm_parameter_values 
+     where parameter_id = v_parameter_id 
+     and package_id is null;
+    update apm_parameter_values set attr_value = set_value__attr_value
+     where value_id = v_value_id;
+    update acs_objects set last_modified = now() 
+     where object_id = v_value_id;
+   --  exception 
+     if NOT FOUND
+       then
+         v_value_id := apm_parameter_value__new(
+            null,
+            null,
+            v_parameter_id,
+            set_value__attr_value
+         );
+     end if;
 
-    PERFORM apm__set_value(
-	v_parameter_id,
-	set_value__package_id,
-	set_value__attr_value
-    );
-
     return 0; 
 end;' language 'plpgsql';
 
-
-
--- show errors
-
--- create or replace package body apm_package
--- procedure initialize_parameters
-
 create or replace function apm_package__is_child(varchar, varchar) returns boolean as '
 declare
   parent_package_key       alias for $1;
@@ -1574,7 +1680,7 @@
     from apm_package_versions apv, apm_package_dependencies apd
     where apd.version_id = apv.version_id
       and apv.enabled_p
-      and apd.dependency_type = ''extends''
+      and apd.dependency_type in (''embeds'', ''extends'')
       and apv.package_key = child_package_key
   loop
     if dependency.service_uri = parent_package_key or
@@ -2586,6 +2692,3 @@
     return 0; 
 end;' language 'plpgsql';
 
-
-
--- show errors
Index: openacs-4/packages/acs-kernel/sql/postgresql/groups-body-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/groups-body-create.sql,v
diff -u -N -r1.31 -r1.32
--- openacs-4/packages/acs-kernel/sql/postgresql/groups-body-create.sql	12 Feb 2009 02:27:02 -0000	1.31
+++ openacs-4/packages/acs-kernel/sql/postgresql/groups-body-create.sql	10 Mar 2010 00:44:03 -0000	1.32
@@ -15,18 +15,18 @@
 
 -- However, PG 7.3 introduces a new type "trigger" for the return type
 -- needed for functions called by triggers.  "create function" transmorgifies
--- the return type "opaque" to "trigger" so PG 7.2 dumps can be restored into
+-- the return type "trigger" to "trigger" so PG 7.2 dumps can be restored into
 -- PG 7.3.  But "create or replace" doesn't do it.   We can't use "trigger"
 -- because we currently are still supporting PG 7.2.  Isn't life a pleasure?
 
 -- I'm leaving the triggers we aren't overriding as "create or replace" because
 -- this will be the right thing to do if the PG folks fix this problem or when
--- we drop support of PG 7.2 and no longer need to declare these as type "opaque"
+-- we drop support of PG 7.2 and no longer need to declare these as type "trigger"
 
 drop trigger membership_rels_in_tr on membership_rels;
 drop function membership_rels_in_tr ();
 
-create or replace function membership_rels_in_tr () returns opaque as '
+create or replace function membership_rels_in_tr () returns trigger as '
 declare
   v_object_id_one acs_rels.object_id_one%TYPE;
   v_object_id_two acs_rels.object_id_two%TYPE;
@@ -85,7 +85,7 @@
 create trigger membership_rels_in_tr after insert on membership_rels
 for each row execute procedure membership_rels_in_tr ();
 
-create or replace function membership_rels_up_tr () returns opaque as '
+create or replace function membership_rels_up_tr () returns trigger as '
 declare
   map             record;
 begin
@@ -112,7 +112,7 @@
 create trigger membership_rels_up_tr before update on membership_rels
 for each row execute procedure membership_rels_up_tr ();
 
-create or replace function membership_rels_del_tr () returns opaque as '
+create or replace function membership_rels_del_tr () returns trigger as '
 declare
   v_error text;
   map             record;
@@ -143,7 +143,7 @@
 drop trigger composition_rels_in_tr on composition_rels;
 drop function composition_rels_in_tr ();
 
-create or replace function composition_rels_in_tr () returns opaque as '
+create or replace function composition_rels_in_tr () returns trigger as '
 declare
   v_object_id_one acs_rels.object_id_one%TYPE;
   v_object_id_two acs_rels.object_id_two%TYPE;
@@ -253,7 +253,7 @@
 -- TO DO: See if this can be optimized now that the member and component
 -- mapping tables have been combined
 --
-create or replace function composition_rels_del_tr () returns opaque as '
+create or replace function composition_rels_del_tr () returns trigger as '
 declare
   v_object_id_one acs_rels.object_id_one%TYPE;
   v_object_id_two acs_rels.object_id_two%TYPE;
Index: openacs-4/packages/acs-kernel/sql/postgresql/groups-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/groups-create.sql,v
diff -u -N -r1.26 -r1.27
--- openacs-4/packages/acs-kernel/sql/postgresql/groups-create.sql	10 Feb 2009 18:31:54 -0000	1.26
+++ openacs-4/packages/acs-kernel/sql/postgresql/groups-create.sql	10 Mar 2010 00:44:03 -0000	1.27
@@ -412,7 +412,7 @@
 -- sourced. That file will replace these triggers with triggers
 -- that actually do useful work
 
-create function membership_rels_in_tr () returns opaque as '
+create function membership_rels_in_tr () returns trigger as '
 declare
 begin
   raise EXCEPTION ''-20000: Insert to membership rels not yet supported'';
@@ -427,7 +427,7 @@
 -- show errors
 
 
-create function composition_rels_in_tr () returns opaque as '
+create function composition_rels_in_tr () returns trigger as '
 declare
 begin
   raise EXCEPTION ''-20000: Insert to composition rels not yet supported'';
Index: openacs-4/packages/acs-kernel/sql/postgresql/lob.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/lob.sql,v
diff -u -N -r1.5 -r1.6
--- openacs-4/packages/acs-kernel/sql/postgresql/lob.sql	24 Jul 2004 14:44:55 -0000	1.5
+++ openacs-4/packages/acs-kernel/sql/postgresql/lob.sql	10 Mar 2010 00:44:03 -0000	1.6
@@ -24,7 +24,7 @@
 	refcount		integer not null default 0
 );
 
-create or replace function on_lobs_delete() returns opaque as '
+create or replace function on_lobs_delete() returns trigger as '
 begin
 	delete from lob_data where lob_id = old.lob_id;
 	return old;
@@ -51,7 +51,7 @@
 -- and PG 7.0.  The ACS doesn't share LOBs between tables
 -- or rows within a table anyway, I don't think/hope.
 
-create or replace function on_lob_ref() returns opaque as '
+create or replace function on_lob_ref() returns trigger as '
 begin
 	if TG_OP = ''UPDATE'' then
 		if new.lob = old.lob then
Index: openacs-4/packages/acs-kernel/sql/postgresql/rel-constraints-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/rel-constraints-create.sql,v
diff -u -N -r1.16 -r1.17
--- openacs-4/packages/acs-kernel/sql/postgresql/rel-constraints-create.sql	25 Sep 2006 17:59:16 -0000	1.16
+++ openacs-4/packages/acs-kernel/sql/postgresql/rel-constraints-create.sql	10 Mar 2010 00:44:03 -0000	1.17
@@ -496,7 +496,7 @@
 create index rc_segment_required_seg_idx on 
 rc_segment_required_seg_map(required_rel_segment);
 
-create function rel_constraints_ins_tr () returns opaque as '
+create function rel_constraints_ins_tr () returns trigger as '
 declare
         v_rec   record;
 begin
@@ -539,7 +539,7 @@
 on rel_constraints for each row 
 execute procedure rel_constraints_ins_tr ();
 
-create function rel_constraints_del_tr () returns opaque as '
+create function rel_constraints_del_tr () returns trigger as '
 declare
         v_rec   record;
 begin
Index: openacs-4/packages/acs-kernel/sql/postgresql/rel-segments-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/rel-segments-create.sql,v
diff -u -N -r1.13 -r1.14
--- openacs-4/packages/acs-kernel/sql/postgresql/rel-segments-create.sql	25 Sep 2006 17:21:43 -0000	1.13
+++ openacs-4/packages/acs-kernel/sql/postgresql/rel-segments-create.sql	10 Mar 2010 00:44:03 -0000	1.14
@@ -276,7 +276,7 @@
 -- destroyed.  These don't call the above helper functions because we're just
 -- creating the identity row for the party.
 
-create or replace function parties_in_tr () returns opaque as '
+create or replace function parties_in_tr () returns trigger as '
 begin
 
   insert into party_approved_member_map
@@ -291,7 +291,7 @@
 create trigger parties_in_tr after insert on parties
 for each row execute procedure parties_in_tr ();
 
-create or replace function parties_del_tr () returns opaque as '
+create or replace function parties_del_tr () returns trigger as '
 begin
 
   delete from party_approved_member_map
@@ -311,7 +311,7 @@
 -- group with that rel_type.  This was intentional on the part of the aD folks
 -- who added relational segments to ACS 4.2.
 
-create or replace function rel_segments_in_tr () returns opaque as '
+create or replace function rel_segments_in_tr () returns trigger as '
 begin
 
   insert into party_approved_member_map
@@ -328,7 +328,7 @@
 create trigger rel_segments_in_tr before insert on rel_segments
 for each row execute procedure rel_segments_in_tr ();
 
-create or replace function rel_segments_del_tr () returns opaque as '
+create or replace function rel_segments_del_tr () returns trigger as '
 begin
 
   delete from party_approved_member_map
Index: openacs-4/packages/acs-kernel/sql/postgresql/site-nodes-create.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/site-nodes-create.sql,v
diff -u -N -r1.21 -r1.22
--- openacs-4/packages/acs-kernel/sql/postgresql/site-nodes-create.sql	18 Jun 2004 18:21:57 -0000	1.21
+++ openacs-4/packages/acs-kernel/sql/postgresql/site-nodes-create.sql	10 Mar 2010 00:44:03 -0000	1.22
@@ -69,7 +69,7 @@
   return tree_sortkey from site_nodes where node_id = p_node_id;
 end;' language 'plpgsql' stable strict;
 
-create or replace function site_node_insert_tr () returns opaque as '
+create or replace function site_node_insert_tr () returns trigger as '
 declare
         v_parent_sk     varbit default null;
         v_max_value     integer;
@@ -98,7 +98,7 @@
 on site_nodes for each row 
 execute procedure site_node_insert_tr ();
 
-create or replace function site_node_update_tr () returns opaque as '
+create or replace function site_node_update_tr () returns trigger as '
 declare
         v_parent_sk     varbit default null;
         v_max_value     integer;
Index: openacs-4/packages/acs-kernel/sql/postgresql/upgrade/upgrade-5.6.0d5-5.6.0d6.sql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-kernel/sql/postgresql/upgrade/upgrade-5.6.0d5-5.6.0d6.sql,v
diff -u -N
--- /dev/null	1 Jan 1970 00:00:00 -0000
+++ openacs-4/packages/acs-kernel/sql/postgresql/upgrade/upgrade-5.6.0d5-5.6.0d6.sql	10 Mar 2010 00:44:03 -0000	1.1
@@ -0,0 +1,28 @@
+create or replace function apm_package__is_child(varchar, varchar) returns boolean as '
+declare
+  parent_package_key       alias for $1;
+  child_package_key        alias for $2;
+  dependency               record;
+begin
+
+  if parent_package_key = child_package_key then
+    return ''t'';
+  end if;
+
+  for dependency in 
+    select apd.service_uri
+    from apm_package_versions apv, apm_package_dependencies apd
+    where apd.version_id = apv.version_id
+      and apv.enabled_p
+      and apd.dependency_type in (''embeds'', ''extends'')
+      and apv.package_key = child_package_key
+  loop
+    if dependency.service_uri = parent_package_key or
+      apm_package__is_child(parent_package_key, dependency.service_uri) then
+      return ''t'';
+    end if;
+  end loop;
+      
+  return ''f'';
+end;' language 'plpgsql';
+
Index: openacs-4/packages/acs-object-management/www/admin/widget-add-edit-2.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-object-management/www/admin/widget-add-edit-2.tcl,v
diff -u -N -r1.3 -r1.4
--- openacs-4/packages/acs-object-management/www/admin/widget-add-edit-2.tcl	2 Jan 2010 14:04:00 -0000	1.3
+++ openacs-4/packages/acs-object-management/www/admin/widget-add-edit-2.tcl	10 Mar 2010 00:44:03 -0000	1.4
@@ -126,4 +126,4 @@
     ad_script_abort
 }
 
-template::head::add_javascript -src widget-add-edit-2.js
\ No newline at end of file
+template::head::add_javascript -src widget-add-edit-2.js
Index: openacs-4/packages/acs-tcl/tcl/apm-install-procs-oracle.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-install-procs-oracle.xql,v
diff -u -N -r1.16 -r1.17
--- openacs-4/packages/acs-tcl/tcl/apm-install-procs-oracle.xql	19 Jan 2010 22:54:25 -0000	1.16
+++ openacs-4/packages/acs-tcl/tcl/apm-install-procs-oracle.xql	10 Mar 2010 00:44:03 -0000	1.17
@@ -259,6 +259,16 @@
       </querytext>
 </fullquery>
 
+<fullquery name="apm_copy_descendent_params.param_exists">      
+  <querytext>
+    begin
+      :1 := apm.parameter_p(
+               :descendent_package_key,
+               :parameter_name);
+    end;
+  </querytext>
+</fullquery>
+
 <fullquery name="apm_copy_descendent_params.copy_descendent_param">      
   <querytext>
     begin
@@ -276,6 +286,16 @@
   </querytext>
 </fullquery>
 
+<fullquery name="apm_copy_inherited_params.param_exists">      
+  <querytext>
+    begin
+      :1 := apm.parameter_p(
+               :new_package_key,
+               :parameter_name);
+    end;
+  </querytext>
+</fullquery>
+
 <fullquery name="apm_copy_inherited_params.copy_inherited_param">      
   <querytext>
     begin
Index: openacs-4/packages/acs-tcl/tcl/apm-install-procs-postgresql.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-install-procs-postgresql.xql,v
diff -u -N -r1.17 -r1.18
--- openacs-4/packages/acs-tcl/tcl/apm-install-procs-postgresql.xql	19 Jan 2010 22:32:39 -0000	1.17
+++ openacs-4/packages/acs-tcl/tcl/apm-install-procs-postgresql.xql	10 Mar 2010 00:44:03 -0000	1.18
@@ -200,6 +200,12 @@
       </querytext>
 </fullquery>
 
+<fullquery name="apm_copy_descendent_params.param_exists">      
+  <querytext>
+    select apm__parameter_p(:descendent_package_key, :parameter_name);
+  </querytext>
+</fullquery>
+
 <fullquery name="apm_copy_descendent_params.copy_descendent_param">      
   <querytext>
     select apm__register_parameter(null, :descendent_package_key, :parameter_name,
@@ -208,6 +214,12 @@
   </querytext>
 </fullquery>
 
+<fullquery name="apm_copy_inherited_params.param_exists">      
+  <querytext>
+    select apm__parameter_p(:new_package_key, :parameter_name);
+  </querytext>
+</fullquery>
+
 <fullquery name="apm_copy_inherited_params.copy_inherited_param">      
   <querytext>
     select apm__register_parameter(null, :new_package_key, :parameter_name, :description,
Index: openacs-4/packages/acs-tcl/tcl/apm-install-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-install-procs.tcl,v
diff -u -N -r1.100 -r1.101
--- openacs-4/packages/acs-tcl/tcl/apm-install-procs.tcl	19 Jan 2010 22:32:39 -0000	1.100
+++ openacs-4/packages/acs-tcl/tcl/apm-install-procs.tcl	10 Mar 2010 00:44:03 -0000	1.101
@@ -124,20 +124,21 @@
     }
 }
 
-ad_proc -private pkg_info_new { package_key spec_file_path extends provides requires {dependency_p ""} {comment ""}} {
+ad_proc -private pkg_info_new { package_key spec_file_path embeds extends provides requires {dependency_p ""} {comment ""}} {
 
     Returns a datastructure that maintains information about a package.
     @param package_key The key of the package.
     @param spec_file_path The path to the package specification file
-    @param extends A list of packages extended by the package..
+    @param embeds A list of packages to be embedded in the package.
+    @param extends A list of packages extended by the package.
     @param provides A list of dependencies provided by the package.
     @param requires A list of requirements provided by the package..
     @param dependency_p Can the package be installed without violating dependency checking.
     @param comment Some text about the package.  Useful to explain why it fails dependency check.
     @return a list whose first element is a package key and whose second element is a path 
     to the associated .info file.
 } {
-    return [list $package_key $spec_file_path $extends $provides $requires $dependency_p $comment]
+    return [list $package_key $spec_file_path $embeds $extends $provides $requires $dependency_p $comment]
 }
 
 ad_proc -private pkg_info_key {pkg_info} {
@@ -167,44 +168,52 @@
     return [file dirname [pkg_info_spec $pkg_info]]
 }
 
-ad_proc -private pkg_info_extends {pkg_info} {
+ad_proc -private pkg_info_embeds {pkg_info} {
 
-    @return The dependencies provided by the package.
+    @return The "embeds" dependencies of the package.
 
 } {
     return [lindex $pkg_info 2]
 }
 
+ad_proc -private pkg_info_extends {pkg_info} {
+
+    @return The "extends" dependencies of the package.
+
+} {
+    return [lindex $pkg_info 3]
+}
+
 ad_proc -private pkg_info_provides {pkg_info} {
 
     @return The dependencies provided by the package.
 
 } {
-    return [lindex $pkg_info 3]
+    return [lindex $pkg_info 4]
 }
 
 ad_proc -private pkg_info_requires {pkg_info} {
 
-    @return The dependencies required by the package info map.
+    @return The dependencies "requires" dependencies of the package.
 
 } {
-    return [lindex $pkg_info 4]
+    return [lindex $pkg_info 5]
 }
 
 ad_proc -private pkg_info_dependency_p {pkg_info} {
 
     @return Does it pass the dependency checker?  "" Means it has not been run yet.
 
 } {
-    return [lindex $pkg_info 5]
+    return [lindex $pkg_info 6]
 }
 
 ad_proc -private pkg_info_comment {pkg_info} {
 
     @return Any comment specified about this package.
 
 } {
-    return [lindex $pkg_info 6]
+    return [lindex $pkg_info 7]
 }
 
 # DRB: This routine does more than check dependencies, it also parses spec files,
@@ -256,7 +265,9 @@
                     [apm_package_supports_rdbms_p -package_key $package(package.key)] } {
                 lappend install_pend [pkg_info_new \
                                          $package(package.key) \
-                                         $spec_file $package(extends) \
+                                         $spec_file \
+                                         $package(embeds) \
+                                         $package(extends) \
                                          $package(provides) \
                                          $package(requires) \
                                          ""]
@@ -298,7 +309,7 @@
             # Now determine if we can add another package to the install set.
             foreach pkg_info $install_pend {
                 set satisfied_p 1
-                foreach req [concat [pkg_info_extends $pkg_info] [pkg_info_requires $pkg_info]] {
+                foreach req [concat [pkg_info_embeds $pkg_info] [pkg_info_extends $pkg_info] [pkg_info_requires $pkg_info]] {
                     if {[apm_dependency_provided_p -dependency_list $install_in_provides \
                             [lindex $req 0] [lindex $req 1]] != 1} {
                         # Unsatisfied dependency.
@@ -318,6 +329,7 @@
                     lappend install_in [pkg_info_new \
                                            [pkg_info_key $pkg_info] \
                                            [pkg_info_spec $pkg_info] \
+                                           [pkg_info_embeds $pkg_info] \
                                            [pkg_info_extends $pkg_info] \
                                            [pkg_info_provides $pkg_info] \
                                            [pkg_info_requires $pkg_info] \
@@ -340,7 +352,7 @@
 
             foreach pkg_info $install_pend {
                 set satisfied_p 1
-                foreach req [concat [pkg_info_extends $pkg_info] [pkg_info_requires $pkg_info]] {
+                foreach req [concat [pkg_info_embeds $pkg_info] [pkg_info_extends $pkg_info] [pkg_info_requires $pkg_info]] {
                     set counter 0
                     foreach pkg_info_add $pkg_info_all {
                         # Will this package do anything to change whether this requirement has been satisfied?
@@ -381,8 +393,8 @@
     if { [exists_and_not_null install_pend] } {
 	foreach pkg_info $install_pend {
 	    lappend install_in [pkg_info_new [pkg_info_key $pkg_info] [pkg_info_spec $pkg_info] \
-				    [pkg_info_extends $pkg_info] [pkg_info_provides $pkg_info] \
-                                    [pkg_info_requires $pkg_info] \
+				    [pkg_info_embeds $pkg_info] [pkg_info_extends $pkg_info] \
+                                    [pkg_info_provides $pkg_info] [pkg_info_requires $pkg_info] \
 				    "f" $install_error([pkg_info_key $pkg_info])]
 	}
 	return [list 0 $install_in]
@@ -480,14 +492,14 @@
                 array set version $repository($package_key)
 
                 set satisfied_p 1
-                foreach req [concat $version(extends) $version(requires)] {
+                foreach req [concat $version(embeds) $version(extends) $version(requires)] {
                     set req_uri [lindex $req 0]
                     set req_version [lindex $req 1]
 
                     if { ![info exists provided($req_uri)] || \
                              [apm_version_names_compare $provided($req_uri) $req_version]== -1 } {
 
-                        ns_log Debug "apm_dependency_check_new: $package_key extends or requires $req_uri $req_version => failed"
+                        ns_log Debug "apm_dependency_check_new: $package_key embeds, extends or requires $req_uri $req_version => failed"
 
                         set satisfied_p 0
 
@@ -497,7 +509,7 @@
                             set required($req_uri) $req_version
                         }
                     } else {
-                        ns_log Debug "apm_dependency_check_new: $package_key extends or requires $req_uri $req_version => OK"
+                        ns_log Debug "apm_dependency_check_new: $package_key embeds, extends or requires $req_uri $req_version => OK"
                     }
                 }
                 
@@ -609,16 +621,16 @@
             lappend result(packages) $package_key
             
             # Find unsatisfied requirements
-            foreach req [concat $version(extends) $version(requires)] {
+            foreach req [concat $version(embeds) $version(extends) $version(requires)] {
                 set req_uri [lindex $req 0]
                 set req_version [lindex $req 1]
                 if { ![info exists provided($req_uri)] || \
                          [apm_version_names_compare $provided($req_uri) $req_version] == -1 } {
                     lappend failed($package_key) [list $req_uri $req_version]
                     if { [info exists provided($req_uri)] } {
-                        ns_log Debug "apm_dependency_check_new: Failed dependency: $package_key extends/requires $req_uri $req_version, but we only provide $provided($req_uri)"
+                        ns_log Debug "apm_dependency_check_new: Failed dependency: $package_key embeds/extends/requires $req_uri $req_version, but we only provide $provided($req_uri)"
                     } else {
-                        ns_log Debug "apm_dependency_check_new: Failed dependency: $package_key extends/requires $req_uri $req_version, but we don't have it"
+                        ns_log Debug "apm_dependency_check_new: Failed dependency: $package_key embeds/extends/requires $req_uri $req_version, but we don't have it"
                     }
                 }
             }
@@ -694,6 +706,7 @@
             # satisfaction later
             lappend pkg_info_list [pkg_info_new $package(package.key) \
                 $spec_file \
+                $package(embeds) \
                 $package(extends) \
                 $package(provides) \
                 $package(requires) \
@@ -878,7 +891,7 @@
 
 	# Update all other package information.
 	apm_package_install_dependencies -callback $callback \
-            $version(extends) $version(provides) $version(requires) $version_id
+            $version(embeds) $version(extends) $version(provides) $version(requires) $version_id
 	apm_package_install_owners -callback $callback $version(owners) $version_id
         apm_package_install_callbacks -callback $callback $version(callbacks) $version_id
         apm_build_one_package_relationships $package_key
@@ -974,24 +987,32 @@
 
     return $version_id
 }
-
 ad_proc apm_copy_descendent_params { new_package_key } {
     Copy new parameters in the package to its descendents.  Called when a package is
     upgraded.
 } {
     foreach descendent_package_key [nsv_get apm_package_descendents $new_package_key] {
         db_foreach descendent_params {} {
-            db_exec_plsql copy_descendent_param {}
+            if { [db_exec_plsql param_exists {}] } {
+                error "$parameter_name already exists in package $descendent_package_key"
+            } else {
+                db_exec_plsql copy_descendent_param {}
+            }
         }
     }
 }
 
 ad_proc apm_copy_inherited_params { new_package_key } {
-    Copy parameters from a packages ancestors.  Called for an "extends" dependency.
+    Copy parameters from a packages ancestors.  Called for "embeds" and "extends"
+    dependencies.
 } {
-    foreach inherited_package_key [nsv_get apm_package_inherit_order $new_package_key] {
+    foreach inherited_package_key [lrange [nsv_get apm_package_inherit_order $new_package_key] 0 end-1] {
         db_foreach inherited_params {} {
-            db_exec_plsql copy_inherited_param {}
+            if { [db_exec_plsql param_exists {}] } {
+                error "$parameter_name already exists in package $package_key"
+            } else {
+                db_exec_plsql copy_inherited_param {}
+            }
         }
     }
 }
@@ -1319,7 +1340,8 @@
     }
 }
 
-ad_proc -private apm_package_install_dependencies { {-callback apm_dummy_callback} extends provides requires version_id} {
+ad_proc -private apm_package_install_dependencies { {-callback apm_dummy_callback} embeds \
+    extends provides requires version_id} {
 
     Install all package dependencies.
 
@@ -1342,6 +1364,13 @@
 	apm_interface_add $version_id $interface_uri $interface_version
     }
 
+    foreach item $embeds {
+	set dependency_uri [lindex $item 0]
+	set dependency_version [lindex $item 1]
+	ns_log Debug "apm_package_install_dependencies: Registering dependency $dependency_uri, $dependency_version for $version_id"
+	apm_dependency_add embeds $version_id $dependency_uri $dependency_version
+    }
+
     foreach item $extends {
 	set dependency_uri [lindex $item 0]
 	set dependency_version [lindex $item 1]
@@ -2031,7 +2060,7 @@
                 -parent_node $package_node \
                 -array version            
             
-            foreach dependency_type { provides requires extends } {
+            foreach dependency_type { provides requires embeds extends } {
                 set version($dependency_type) {}
                 foreach dependency_node [xml_node_get_children_by_name $package_node "$dependency_type"] {
                     lappend version($dependency_type) \
Index: openacs-4/packages/acs-tcl/tcl/apm-install-procs.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-install-procs.xql,v
diff -u -N -r1.6 -r1.7
--- openacs-4/packages/acs-tcl/tcl/apm-install-procs.xql	19 Jan 2010 22:32:39 -0000	1.6
+++ openacs-4/packages/acs-tcl/tcl/apm-install-procs.xql	10 Mar 2010 00:44:03 -0000	1.7
@@ -94,10 +94,6 @@
     select ap.*
     from apm_parameters ap
     where package_key = :new_package_key
-      and not exists (select 1
-                      from apm_parameters ap2
-                      where ap2.parameter_name = ap.parameter_name
-                        and ap2.package_key = :descendent_package_key)
   </querytext>
 </fullquery>
 
@@ -106,10 +102,6 @@
     select ap.*
     from apm_parameters ap
     where package_key = :inherited_package_key
-      and not exists (select 1
-                      from apm_parameters ap2
-                      where ap2.parameter_name = ap.parameter_name
-                        and ap2.package_key = :new_package_key)
    </querytext>
 </fullquery>
  
Index: openacs-4/packages/acs-tcl/tcl/apm-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-procs.tcl,v
diff -u -N -r1.83 -r1.84
--- openacs-4/packages/acs-tcl/tcl/apm-procs.tcl	12 Jul 2009 01:08:30 -0000	1.83
+++ openacs-4/packages/acs-tcl/tcl/apm-procs.tcl	10 Mar 2010 00:44:03 -0000	1.84
@@ -177,29 +177,41 @@
 
 }
 
-ad_proc apm_package_list_search_order {
+ad_proc apm_package_list_url_resolution {
     package_list
 } {
-    Left-right, breadth-first traverse of the inheritance DAG.
+    Use a left-right, breadth-first traverse of the inheritance DAG to build a
+    structure to be used by the request processor to resolve URLs based on a
+    package's "extends" and "embeds" dependencies.
 } {
     global apm_visited_package_keys
-    global apm_package_search_order
+    global apm_package_url_resolution
 
-    foreach package_key $package_list {
+    foreach package $package_list {
+        foreach {package_key dependency_type} $package {}
         if { [info exists apm_visited_package_keys($package_key)] } {
             continue
         }
-        lappend apm_package_search_order $package_key
+        switch $dependency_type {
+            extends -
+            "" { lappend apm_package_url_resolution [acs_root_dir]/packages/$package_key/www }
+            embeds { lappend apm_package_url_resolution \
+                          [list [acs_root_dir]/packages/$package_key/embed $package_key]
+                    }
+            default {
+                error "apm_package_list_url_resolution: dependency type is $dependency_type"
+            }
+        }
         set apm_visited_package_keys($package_key) 1
     }
 
     # Make sure old versions work ...
-    foreach package_key $package_list {
-        set inherit_templates_p 1
+    foreach package $package_list {
+        foreach {package_key dependency_type} $package {}
+        set inherit_templates_p t
+#fix!
         catch { db_1row get_inherit_templates_p {} }
-        if { [string is true $inherit_templates_p] } {
-            apm_package_list_search_order [db_list get_dependencies {}]
-        }
+        apm_package_list_url_resolution [db_list_of_lists get_dependencies {}]
     }
 }
 
@@ -255,15 +267,15 @@
 
 } {
     global apm_visited_package_keys
-    global apm_package_search_order
+    global apm_package_url_resolution
     global apm_package_inherit_order
     global apm_package_load_libraries_order
     global apm_package_descendents
 
     array unset apm_visited_package_keys
-    set apm_package_search_order [list]
-    apm_package_list_search_order $package_key
-    nsv_set apm_package_search_order $package_key $apm_package_search_order
+    set apm_package_url_resolution [list]
+    apm_package_list_url_resolution $package_key
+    nsv_set apm_package_url_resolution $package_key $apm_package_url_resolution
 
     array unset apm_visited_package_keys
     set apm_package_inherit_order [list]
@@ -295,39 +307,32 @@
 ad_proc apm_package_descendents {
     package_key
 } {
-
     Wrapper that returns the cached package descendents list.
-
 } {
     return [nsv_get apm_package_descendents $package_key]
 }
 
 ad_proc apm_package_inherit_order {
     package_key
 } {
-
     Wrapper that returns the cached package inheritance order list.
-
 } {
     return [nsv_get apm_package_inherit_order $package_key]
 }
 
-ad_proc apm_package_search_order {
+ad_proc apm_package_url_resolution {
     package_key
 } {
-
     Wrapper that returns the cached package search order list.
-
 } {
-    return [nsv_get apm_package_search_order $package_key]
+    return [nsv_get apm_package_url_resolution $package_key]
 }
 
+
 ad_proc apm_package_load_libraries_order {
     package_key
 } {
-
     Wrapper that returns the cached package library load order list.
-
 } {
     return [nsv_get apm_package_load_libraries_order $package_key]
 }
@@ -2051,6 +2056,7 @@
         site_node::update_cache -node_id $node_id
     }
 
+# DRB: parameter fix!
     db_foreach get_params {} {
         db_1row get_new_parameter_id {}
         db_dml update_param {}
Index: openacs-4/packages/acs-tcl/tcl/apm-procs.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-procs.xql,v
diff -u -N -r1.25 -r1.26
--- openacs-4/packages/acs-tcl/tcl/apm-procs.xql	17 Mar 2009 01:11:07 -0000	1.25
+++ openacs-4/packages/acs-tcl/tcl/apm-procs.xql	10 Mar 2010 00:44:03 -0000	1.26
@@ -7,7 +7,7 @@
       from apm_package_versions apv, apm_package_dependencies apd
       where apd.version_id = apv.version_id
         and apv.enabled_p = 't'
-        and apd.dependency_type = 'extends'
+        and apd.dependency_type in ('extends', 'embeds')
         and apd.service_uri = :package_key
     </querytext>
   </fullquery>
@@ -20,22 +20,35 @@
     </querytext>
   </fullquery>
 
-  <fullquery name="apm_package_list_search_order.get_inherit_templates_p">
+  <fullquery name="apm_package_list_search_order.get_dependencies">
     <querytext>
+      select apd.service_uri
+      from apm_package_versions apv, apm_package_dependencies apd
+      where apv.package_key = :package_key
+        and apv.installed_p = 't'
+        and apd.version_id = apv.version_id
+        and apd.dependency_type in ('extends', 'embeds')
+      order by apd.dependency_id
+    </querytext>
+  </fullquery>
+
+  <fullquery name="apm_package_list_url_resolution.get_inherit_templates_p">
+    <querytext>
       select inherit_templates_p
       from apm_package_types
       where package_key = :package_key
     </querytext>
   </fullquery>
 
-  <fullquery name="apm_package_list_search_order.get_dependencies">
+  <fullquery name="apm_package_list_url_resolution.get_dependencies">
     <querytext>
-      select apd.service_uri
+      select apd.service_uri, apd.dependency_type
       from apm_package_versions apv, apm_package_dependencies apd
       where apv.package_key = :package_key
         and apv.installed_p = 't'
         and apd.version_id = apv.version_id
-        and apd.dependency_type = 'extends'
+        and (apd.dependency_type = 'embeds'
+             or apd.dependency_type =  'extends' and :inherit_templates_p = 't')
       order by apd.dependency_id
     </querytext>
   </fullquery>
@@ -47,7 +60,7 @@
       where apv.package_key = :package_key
         and apv.installed_p = 't'
         and apd.version_id = apv.version_id
-        and apd.dependency_type = 'extends'
+        and apd.dependency_type in ('extends', 'embeds')
       order by apd.dependency_id desc
     </querytext>
   </fullquery>
@@ -59,7 +72,7 @@
       where apv.package_key = :package_key
         and apv.installed_p = 't'
         and apd.version_id = apv.version_id
-        and apd.dependency_type in ('requires', 'extends')
+        and apd.dependency_type in ('requires', 'embeds', 'extends')
       order by apd.dependency_id desc
     </querytext>
   </fullquery>
Index: openacs-4/packages/acs-tcl/tcl/apm-xml-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/apm-xml-procs.tcl,v
diff -u -N -r1.27 -r1.28
--- openacs-4/packages/acs-tcl/tcl/apm-xml-procs.tcl	25 Nov 2008 17:08:50 -0000	1.27
+++ openacs-4/packages/acs-tcl/tcl/apm-xml-procs.tcl	10 Mar 2010 00:44:03 -0000	1.28
@@ -169,7 +169,8 @@
     <ul>
     <li><code>path</code>: a path to the file read
     <li><code>mtime</code>: the mtime of the file read
-    <li><code>provides</code>, <code>extends</code>, and <code>requires</code>:
+    <li><code>provides</code>, <code>embeds</code>, <code>extends</code>,
+      and <code>requires</code>: <p>
       lists of dependency information, containing elements of the form
       <code>[list $url $version]</code>
     <li><code>owners</code>: a list of owners containing elements of the form
@@ -311,9 +312,10 @@
 
     set properties(provides) [list]
     set properties(requires) [list]
+    set properties(embeds) [list]
     set properties(extends) [list]
 
-    foreach dependency_type { provides requires extends } {
+    foreach dependency_type { provides requires embeds extends } {
 	set dependency_types [xml_node_get_children_by_name $version $dependency_type]
 
 	foreach node $dependency_types {
Index: openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl,v
diff -u -N -r1.62 -r1.63
--- openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl	15 Sep 2009 22:58:32 -0000	1.62
+++ openacs-4/packages/acs-tcl/tcl/form-processing-procs.tcl	10 Mar 2010 00:44:03 -0000	1.63
@@ -794,6 +794,7 @@
                             return -code error "element $element_name: a form can only declare one key"
                         }
                         set af_key_name($form_name) $element_name
+                        set af_type(${form_name}__$element_name) integer
                         if { $af_element_parameters($element_name:key) ne "" } {
                             if { [info exists af_sequence_name($form_name)] } {
                                 return -code error "element $element_name: duplicate sequence"
@@ -802,6 +803,7 @@
                         }
                         lappend form_command "-datatype" "integer" "-widget" "hidden"
                         template::element create $form_name __key_signature -datatype text -widget hidden -value ""
+                        template::element create $form_name __key -datatype text -widget hidden -value $element_name
                         template::element create $form_name __new_p -datatype integer -widget hidden -value 0
                     }
 
@@ -869,17 +871,17 @@
     foreach element_name $af_element_names($form_name) {
         if { [llength $element_name] == 1 } {
             if { [info exists af_from_sql(${form_name}__$element_name)] } {
-                if { [empty_string_p [info commands "::template::util::$af_type(${form_name}__$element_name)::acquire"]] } {
+                if { [info commands "::template::util::$af_type(${form_name}__$element_name)::acquire"] eq "" } {
                     return -code error "\"from_sql\" not valid for type \"$af_type(${form_name}__$element_name)\""
                 }
             }
             if { [info exists af_to_sql(${form_name}__$element_name)] } {
-                if { [empty_string_p [info commands "::template::util::$af_type(${form_name}__$element_name)::get_property"]] } {
+                if { [info commands ::template::util::$af_type(${form_name}__$element_name)::get_property] eq "" } {
                     return -code error "\"to_sql\" not valid for type \"$af_type(${form_name}__$element_name)\""
                 }
             }
             if { [info exists af_to_html(${form_name}__$element_name)] } {
-                if { [empty_string_p [info commands "::template::util::$af_type(${form_name}__$element_name)::get_property"]] } {
+                if { [empty_string_p [info commands ::template::util::$af_type(${form_name}__$element_name)::get_property]] } {
                     return -code error "\"to_html\" not valid for type \"$af_type(${form_name}__$element_name)\""
                 }
             }
@@ -969,6 +971,8 @@
                             if { [info exists af_from_sql(${form_name}__$element_name)] } {
                                 set values($element_name) [template::util::$af_type(${form_name}__$element_name)::acquire \
                                                            $af_from_sql(${form_name}__$element_name) $values($element_name)]
+                            } elseif { [info commands ::template::data::from_sql::$af_type(${form_name}__$element_name)] ne "" } {
+                                set values($element_name) [template::data::from_sql::$af_type(${form_name}__$element_name) $values($element_name)]
                             }
                         }
                     }
Index: openacs-4/packages/acs-tcl/tcl/parameter-procs-oracle.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/parameter-procs-oracle.xql,v
diff -u -N -r1.1 -r1.2
--- openacs-4/packages/acs-tcl/tcl/parameter-procs-oracle.xql	15 May 2002 18:47:31 -0000	1.1
+++ openacs-4/packages/acs-tcl/tcl/parameter-procs-oracle.xql	10 Mar 2010 00:44:03 -0000	1.2
@@ -3,6 +3,18 @@
 <queryset>
     <rdbms><type>oracle</type><version>8.1.6</version></rdbms>
 
+    <fullquery name="parameter::set_global_value.set_parameter_value">
+        <querytext>
+            begin
+                apm.set_value(
+                    package_key => :package_key,
+                    parameter_name => :parameter,
+                    attr_value => :value
+                );
+            end;
+        </querytext>
+    </fullquery>
+
     <fullquery name="parameter::set_value.set_parameter_value">
         <querytext>
             begin
Index: openacs-4/packages/acs-tcl/tcl/parameter-procs-postgresql.xql
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/parameter-procs-postgresql.xql,v
diff -u -N -r1.1 -r1.2
--- openacs-4/packages/acs-tcl/tcl/parameter-procs-postgresql.xql	16 May 2002 18:36:29 -0000	1.1
+++ openacs-4/packages/acs-tcl/tcl/parameter-procs-postgresql.xql	10 Mar 2010 00:44:03 -0000	1.2
@@ -3,10 +3,20 @@
 <queryset>
     <rdbms><type>postgresql</type><version>7.1</version></rdbms>
 
+    <fullquery name="parameter::set_global_value.set_parameter_value">
+        <querytext>
+            select apm__set_value(
+                :package_key::varchar,
+                :parameter,
+                :value
+            );
+        </querytext>
+    </fullquery>
+
     <fullquery name="parameter::set_value.set_parameter_value">
         <querytext>
             select apm__set_value(
-                :package_id,
+                :package_id::integer,
                 :parameter,
                 :value
             );
Index: openacs-4/packages/acs-tcl/tcl/parameter-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/parameter-procs.tcl,v
diff -u -N -r1.16 -r1.17
--- openacs-4/packages/acs-tcl/tcl/parameter-procs.tcl	10 Jan 2007 21:22:12 -0000	1.16
+++ openacs-4/packages/acs-tcl/tcl/parameter-procs.tcl	10 Mar 2010 00:44:03 -0000	1.17
@@ -26,12 +26,93 @@
     db_dml set {}
 }
 
+ad_proc -public parameter::set_global_value {
+    {-package_key:required}
+    {-parameter:required}
+    {-value:required}
+} {
+    Set a global package parameter.
+
+    Do not confuse this with the proc "set_from_package_key", which was previously
+    used to emulate global parameters declared for singleton packages.
+
+    @param package_key identifies the package to which the global param belongs
+    @param parameter which parameter's value to set
+    @param value what value to set said parameter to
+} {
+
+    db_exec_plsql set_parameter_value {}
+
+    return [ad_parameter_cache -set $value $package_id $parameter]
+}
+
+ad_proc -public parameter::get_global_value {
+    -localize:boolean
+    -boolean:boolean
+    {-package_key:required}
+    {-parameter:required}
+    {-default ""}
+} {
+    Get the value of a global package parameter.
+
+    @param localize should we attempt to localize the parameter 
+    @param boolean insure boolean parameters are normalized to 0 or 1
+    @param package_key identifies the package to which the global param belongs
+    @param parameter which parameter's value to get
+    @param default what to return if we don't find a value. Defaults to returning the empty string.
+
+    @return The string trimmed (leading and trailing spaces removed) parameter value
+} {
+
+    # Is there a parameter by this name in the parameter file?  If so, it takes precedence.
+    # Note that this makes *far* more sense for global parameters than for package instance
+    # parameters.
+
+    # 1. use the parameter file
+    set value [ad_parameter_from_file $parameter $package_key]
+
+    # 2. check the parameter cache
+    if {$value eq ""} {
+        set value [ad_parameter_cache $package_id $parameter]
+    }
+    # 3. use the default value
+    if {$value eq ""} {
+        set value $default
+    }
+
+    if { $localize_p } {
+        # Replace message keys in hash marks with localized texts
+        set value [lang::util::localize $value]
+    }
+
+    # Trimming the value as people may have accidentally put in trailing spaces
+    set value [string trim $value]
+
+    # Special parsing for boolean parameters, true and false can be written
+    # in many different ways
+    if { $boolean_p } {
+        if { [catch { 
+            if { [template::util::is_true $value] } {
+                set value 1
+            } else {
+                set value 0
+            }
+        } errmsg] } {
+            global errorInfo
+            ns_log Error "Parameter $parameter not a boolean:\n$errorInfo"
+            set value $default
+        }
+    }
+
+    return $value
+}
+
 ad_proc -public parameter::set_value {
     {-package_id ""}
     {-parameter:required}
     {-value:required}
 } {
-    set a parameter
+    Set the value of a package instance parameter
 
     @param package_id what package to set the parameter in. defaults to
     [ad_conn package_id]
@@ -54,7 +135,7 @@
     {-parameter:required}
     {-default ""}
 } {
-    Get the value of a package parameter.
+    Get the value of a package instance parameter.
 
     @param localize should we attempt to localize the parameter 
     @param boolean insure boolean parameters are normalized to 0 or 1
@@ -131,10 +212,13 @@
     {-parameter:required}
     {-value:required}
 } {
-    sets a parameter for the package corresponding to package_key
-    note that this makes the assumption that the package is a singleton
-    and does not set the value for all packages corresponding to package_key
+    sets an instance parameter for the package corresponding to package_key.
+    
+    Note that this makes the assumption that the package is a singleton
+    and does not set the value for all packages corresponding to package_key.
 
+    New packages should use global parameters instead.
+
 } {
     parameter::set_value \
         -package_id [apm_package_id_from_key $package_key] \
@@ -149,8 +233,12 @@
     {-parameter:required}
     {-default ""}
 } {
-    get a parameter
+    Gets an instance parameter for the package corresponding to package_key.
+    
+    Note that this makes the assumption that the package is a singleton.
 
+    New packages should use global parameters instead.
+
     @param package_key what package to get the parameter from. we will try
     to get the package_id from the package_key. this
     may cause an error if there are more than one
Index: openacs-4/packages/acs-tcl/tcl/request-processor-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/request-processor-procs.tcl,v
diff -u -N -r1.100 -r1.101
--- openacs-4/packages/acs-tcl/tcl/request-processor-procs.tcl	2 Feb 2010 22:33:54 -0000	1.100
+++ openacs-4/packages/acs-tcl/tcl/request-processor-procs.tcl	10 Mar 2010 00:44:03 -0000	1.101
@@ -34,12 +34,12 @@
     the current directory, relative links returned to the clients
     browser may be broken (since the client will have the original URL).
 
-    Use rp_form_put if you want to feed query variables to the redirected page.
+    Use rp_form_put or rp_form_update if you want to feed query variables to the redirected page.
     
     @param absolute_path If set the path is an absolute path within the host filesystem
     @param path path to the file to serve
 
-    @see rp_form_put
+    @see rp_form_put, rp_form_update
 
 } {
 
@@ -861,31 +861,36 @@
       rp_debug -debug t "error in rp_handler: $errmsg"
     }
 
-    set roots [ns_info pageroot][string trimright [ad_conn package_url] /]
+    set resolve_values [concat [ns_info pageroot][string trimright [ad_conn package_url] /] \
+                               [apm_package_url_resolution [ad_conn package_key]]]
 
-    if { [ad_conn package_key] ne "" } {
-        foreach package_key [apm_package_search_order [ad_conn package_key]] {
-            lappend roots [acs_root_dir]/packages/$package_key/www
+    foreach resolve_value $resolve_values {
+        foreach {root match_prefix} $resolve_value {}
+        set extra_url [ad_conn extra_url]
+        if { $match_prefix ne "" } {
+            if { [string first $match_prefix $extra_url] == 0 } {
+                set extra_url [string trimleft \
+                    [string range $extra_url [string length $match_prefix] end] /]
+            } else {
+                continue
+            }
         }
-    }
-
-    foreach root $roots {
-        ds_add rp [list notice "Trying rp_serve_abstract_file $root/[ad_conn extra_url]" $startclicks [clock clicks -milliseconds]]
+        ds_add rp [list notice "Trying rp_serve_abstract_file $root/$extra_url" $startclicks [clock clicks -milliseconds]]
         ad_try {
-            rp_serve_abstract_file "$root/[ad_conn extra_url]"
+            rp_serve_abstract_file "$root/$extra_url"
             set tcl_url2file([ad_conn url]) [ad_conn file]
             set tcl_url2path_info([ad_conn url]) [ad_conn path_info]
         } notfound val {
-            ds_add rp [list notice "File $root/[ad_conn extra_url]: Not found" $startclicks [clock clicks -milliseconds]]
-            ds_add rp [list transformation [list notfound "$root / [ad_conn extra_url]" $val] $startclicks [clock clicks -milliseconds]]
+            ds_add rp [list notice "File $root/$extra_url: Not found" $startclicks [clock clicks -milliseconds]]
+            ds_add rp [list transformation [list notfound "$root / $extra_url" $val] $startclicks [clock clicks -milliseconds]]
             continue
         } redirect url {
-            ds_add rp [list notice "File $root/[ad_conn extra_url]: Redirect" $startclicks [clock clicks -milliseconds]]
-            ds_add rp [list transformation [list redirect $root/[ad_conn extra_url] $url] $startclicks [clock clicks -milliseconds]]
+            ds_add rp [list notice "File $root/$extra_url: Redirect" $startclicks [clock clicks -milliseconds]]
+            ds_add rp [list transformation [list redirect $root/$extra_url $url] $startclicks [clock clicks -milliseconds]]
             ad_returnredirect $url
         } directory dir_index {
-            ds_add rp [list notice "File $root/[ad_conn extra_url]: Directory index" $startclicks [clock clicks -milliseconds]]
-            ds_add rp [list transformation [list directory $root/[ad_conn extra_url] $dir_index] $startclicks [clock clicks -milliseconds]]
+            ds_add rp [list notice "File $root/$extra_url: Directory index" $startclicks [clock clicks -milliseconds]]
+            ds_add rp [list transformation [list directory $root/$extra_url $dir_index] $startclicks [clock clicks -milliseconds]]
             continue
         }
         return
@@ -904,30 +909,40 @@
     # OK, we didn't find a normal file. Let's look for a path info style thingy,
     # visiting possible file matches from most specific to least.
 
-    foreach prefix [rp_path_prefixes [ad_conn extra_url]] {
-        foreach root $roots {
+    foreach prefix [rp_path_prefixes $extra_url] {
+        foreach resolve_value $resolve_values {
+            foreach {root match_prefix} $resolve_value {}
+            set extra_url [ad_conn extra_url]
+            if { $match_prefix ne "" } {
+                if { [string first $match_prefix $extra_url] == 0 } {
+                    set extra_url [string trimleft \
+                        [string range $extra_url [string length $match_prefix] end] /]
+                } else {
+                    continue
+                }
+            }
             ad_try {
                 ad_conn -set path_info \
-                    [string range [ad_conn extra_url] [expr {[string length $prefix] - 1}] end]
+                    [string range $extra_url [expr {[string length $prefix] - 1}] end]
                 rp_serve_abstract_file -noredirect -nodirectory \
                     -extension_pattern ".vuh" "$root$prefix"
                     set tcl_url2file([ad_conn url]) [ad_conn file]
                     set tcl_url2path_info([ad_conn url]) [ad_conn path_info]
                 } notfound val {
-                    ds_add rp [list transformation [list notfound $root/[ad_conn extra_url] $val] $startclicks [clock clicks -milliseconds]]
+                    ds_add rp [list transformation [list notfound $root$prefix $val] $startclicks [clock clicks -milliseconds]]
                     continue
                 } redirect url {
-                    ds_add rp [list transformation [list redirect $root/[ad_conn extra_url] $url] $startclicks [clock clicks -milliseconds]]
+                    ds_add rp [list transformation [list redirect $root$prefix $url] $startclicks [clock clicks -milliseconds]]
                     ad_returnredirect $url
                 } directory dir_index {
-                    ds_add rp [list transformation [list directory $root/[ad_conn extra_url] $dir_index] $startclicks [clock clicks -milliseconds]]
+                    ds_add rp [list transformation [list directory $root$prefix $dir_index] $startclicks [clock clicks -milliseconds]]
                     continue
                 }
             return
         }
     }
 
-    ds_add rp [list transformation [list notfound $root/[ad_conn extra_url] notfound] $startclicks [clock clicks -milliseconds]]
+    ds_add rp [list transformation [list notfound $root/$extra_url notfound] $startclicks [clock clicks -milliseconds]]
     ns_returnnotfound
   } errmsg]] } {
     if {$code == 1} {
Index: openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl,v
diff -u -N -r1.118 -r1.119
--- openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl	16 Jan 2010 23:01:04 -0000	1.118
+++ openacs-4/packages/acs-tcl/tcl/utilities-procs.tcl	10 Mar 2010 00:44:03 -0000	1.119
@@ -1506,6 +1506,16 @@
     return [expr { [info exists var] && $var ne "" }] 
 } 
 
+ad_proc -public exists_or_null { varname } {
+    Returns the contents of the variable if it exists, otherwise returns empty string
+} {
+    upvar 1 $varname var
+    if {[info exists var]} {
+        return $var
+    }
+    return ""
+}
+
 ad_proc -public exists_and_equal { varname value } {
     Returns 1 if the variable name exists in the caller's envirnoment
     and is equal to the given value.