Index: TODO
===================================================================
diff -u -r8c8969ab850d118f76305689bd95e980b8f4543f -r8f4072d4e6bb8bae0ab7ef7e0b78526ad7852453
--- TODO	(.../TODO)	(revision 8c8969ab850d118f76305689bd95e980b8f4543f)
+++ TODO	(.../TODO)	(revision 8f4072d4e6bb8bae0ab7ef7e0b78526ad7852453)
@@ -3958,7 +3958,14 @@
 - make ::nsf::log more robust for aolserver/naviserver, since ::ns_log is 
   not always around when an output is needed
 
+- serializer:
+  * make [::Serializer deepSerialize -ignoreVarsRE "" $o] behave like
+    [::Serializer deepSerialize $o], since learn@wu depends on that, and
+    a value for ignoreVarsRE of empty looks more like an omitted value than
+    a regular expression, that should match everything.
+  * extended regression test
 
+
 ========================================================================
 TODO:
 
Index: library/serialize/serializer.tcl
===================================================================
diff -u -rf9dcf9b0efaa245cf8839e9de9e1e5c5f0d3d018 -r8f4072d4e6bb8bae0ab7ef7e0b78526ad7852453
--- library/serialize/serializer.tcl	(.../serializer.tcl)	(revision f9dcf9b0efaa245cf8839e9de9e1e5c5f0d3d018)
+++ library/serialize/serializer.tcl	(.../serializer.tcl)	(revision 8f4072d4e6bb8bae0ab7ef7e0b78526ad7852453)
@@ -566,8 +566,9 @@
     :method collectVars {o s} {
       set setcmd [list]
       foreach v [lsort [$o info vars]] {
-        if {![::nsf::var::exists $s ignoreVarsRE] || \
-		![regexp [::nsf::var::set $s ignoreVarsRE] ${o}::$v]} {
+        if {![::nsf::var::exists $s ignoreVarsRE] 
+	    || [::nsf::var::set $s ignoreVarsRE] eq "" 
+	    || ![regexp [::nsf::var::set $s ignoreVarsRE] ${o}::$v]} {
 	  if {[::nsf::var::exists $o $v] == 0} {
 	    puts stderr "strange, [list $o info vars] returned $v, but it does not seem to exist"
 	    continue
Index: tests/serialize.test
===================================================================
diff -u -rf9dcf9b0efaa245cf8839e9de9e1e5c5f0d3d018 -r8f4072d4e6bb8bae0ab7ef7e0b78526ad7852453
--- tests/serialize.test	(.../serialize.test)	(revision f9dcf9b0efaa245cf8839e9de9e1e5c5f0d3d018)
+++ tests/serialize.test	(.../serialize.test)	(revision 8f4072d4e6bb8bae0ab7ef7e0b78526ad7852453)
@@ -71,10 +71,11 @@
   ? {c1 a 1} 1
   ? {c1 b 1} 1
 
-  set c1(All) [list [::Serializer deepSerialize c1] "a b"]
+  set c1(IgnoreNone1) [list [::Serializer deepSerialize c1] "a b"]
+  set c1(IgnoreNone2) [list [::Serializer deepSerialize -ignoreVarsRE "" c1] "a b"]
   set c1(One) [list [::Serializer deepSerialize -ignoreVarsRE "a" c1] "b"]
   set c1(One2) [list [::Serializer deepSerialize -ignoreVarsRE {::a$} c1] "b"]
-  set c1(None1) [list [::Serializer deepSerialize -ignoreVarsRE "" c1] ""]
+  set c1(IgnoreAll) [list [::Serializer deepSerialize -ignoreVarsRE "." c1] ""]
   set c1(None2) [list [::Serializer deepSerialize -ignoreVarsRE \
 			   [join [C info slot names] |] c1] ""]
   
@@ -90,10 +91,11 @@
   }
 
   
-  set C(All) [list [::Serializer deepSerialize C] "x y"]
+  set C(IgnoreNone1) [list [::Serializer deepSerialize C] "x y"]
+  set C(IgnoreNone2) [list [::Serializer deepSerialize -ignoreVarsRE "" C] "x y"]
   set C(One) [list [::Serializer deepSerialize -ignoreVarsRE "x" C] "y"]
   set C(One2) [list [::Serializer deepSerialize -ignoreVarsRE {::x$} C] "y"]
-  set C(None1) [list [::Serializer deepSerialize -ignoreVarsRE "" C] ""]
+  set C(IgnoreAll) [list [::Serializer deepSerialize -ignoreVarsRE "." C] ""]
   set C(None2) [list [::Serializer deepSerialize \
 			  -ignoreVarsRE [join [C class info slot names] |] C] ""]