Index: openacs-4/packages/acs-tcl/tcl/community-core-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/acs-tcl/tcl/community-core-procs.tcl,v
diff -u -r1.30 -r1.31
--- openacs-4/packages/acs-tcl/tcl/community-core-procs.tcl	18 Sep 2003 17:08:38 -0000	1.30
+++ openacs-4/packages/acs-tcl/tcl/community-core-procs.tcl	24 Sep 2003 17:30:29 -0000	1.31
@@ -104,9 +104,35 @@
         set url [db_null]
     }
 
+    if { [empty_string_p $authority_id] } {
+        set authority_id [auth::authority::local]
+    }
+
     # Lars: This is a hack until we sort out the UsernameIsEmail situation
-    if { [empty_string_p $username] } {
-        set username $email
+    if { [auth::UseEmailForLoginP] && [empty_string_p $username] } {
+        # Generate a username that's guaranteed to be unique
+        # Rather much work, but that's the best I could think of
+
+        set username [string tolower $email]
+        set existing_user_id [acs_user::get_by_username -authority_id $authority_id -username $username]
+        if { ![empty_string_p $existing_user_id] } {
+            set match "$username-%"
+            set existing_usernames [db_list select_existing_usernames { 
+                select username 
+                from   users
+                where  authority_id = :authority_id
+                and    username like :match
+            }]
+            set number 2
+            foreach existing_username $existing_usernames {
+                if { [regexp "^${username}-(\\d+)\$" $url match n] } {
+                    # matches the foo-123 pattern
+                    if { $n >= $number } { set number [expr $n + 1] }
+                }
+            }
+            set username "$username-$number"
+            ns_log Notice "User's email was already used as someone else's username, setting username to $username"
+        }
     }
 
     set creation_user ""