Index: openacs-4/packages/xowiki/tcl/xowiki-utility-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/xowiki-utility-procs.tcl,v
diff -u -N -r1.57.2.22 -r1.57.2.23
--- openacs-4/packages/xowiki/tcl/xowiki-utility-procs.tcl	29 Mar 2021 08:34:19 -0000	1.57.2.22
+++ openacs-4/packages/xowiki/tcl/xowiki-utility-procs.tcl	22 Jun 2021 17:34:28 -0000	1.57.2.23
@@ -172,23 +172,31 @@
   #
   # Helper functions for hstore
   #
+  set ::xowiki::hstore::max_value_size [parameter::get_global_value \
+                                            -package_key xowiki \
+                                            -parameter hstore_max_value_size \
+                                            -default 0]
+
   ad_proc double_quote {value} {
+
+    From hstore manual: "Double-quote keys and values that include
+    whitespace, commas, =s or >s. To include a double quote or a
+    backslash in a key or value, escape it with a backslash."
+    https://www.postgresql.org/docs/current/hstore.html
+
     @return double_quoted value as appropriate for hstore
   } {
-    if {[regexp {[ ,\"\\=>\n\']} $value]} {
-      set value \"[string map [list \" \\\" \\ \\\\ ' ''] $value]\"
+    if {[regexp {[\s,\"\'\\=>]} $value]} {
+      return \"[string map [list \" \\\" \\ \\\\ ' ''] $value]\"
     }
     return $value
   }
 
   ad_proc dict_as_hkey {dict} {
     @return dict value in form of a hstore key.
   } {
-    set max_value_size [parameter::get_global_value \
-                            -package_key xowiki \
-                            -parameter hstore_max_value_size \
-                            -default 0]
     set keys {}
+    variable ::xowiki::hstore::max_value_size
     foreach {key value} $dict {
       set v [double_quote $value]
       if {$v eq ""
Index: openacs-4/packages/xowiki/tcl/test/api-test-procs.tcl
===================================================================
RCS file: /usr/local/cvsroot/openacs-4/packages/xowiki/tcl/test/Attic/api-test-procs.tcl,v
diff -u -N -r1.1.2.11 -r1.1.2.12
--- openacs-4/packages/xowiki/tcl/test/api-test-procs.tcl	21 Jun 2021 13:51:51 -0000	1.1.2.11
+++ openacs-4/packages/xowiki/tcl/test/api-test-procs.tcl	22 Jun 2021 17:34:28 -0000	1.1.2.12
@@ -117,10 +117,10 @@
         Checks conversion from dict to hstorage keys with proper escaping
 
     } {
-        set dict {key1 value1 key2 a'b k'y value3 key4 1,2}
+        set dict {key1 value1 key2 a'b k'y value3 key4 1,2 c before\tafter d "hello world"}
         aa_equals "filter option_list with empty exclusion set" \
-            [::xowiki::hstore::dict_as_hkey  $dict] \
-            {key1=>value1,key2=>"a''b","k''y"=>value3,key4=>"1,2"}
+            [::xowiki::hstore::dict_as_hkey $dict] \
+            {key1=>value1,key2=>"a''b","k''y"=>value3,key4=>"1,2",c=>"before	after",d=>"hello world"}
     }
 #
 # Local variables: