Instance XML does not have to be set.

But whenever it is set, it shall be correct XML.

master/bt5/vifib_base/PropertySheetTemplateItem/portal_property_sheets/SoftwareInstanceConstraint/text_content_existence_constraint.xml

-<?xml version="1.0"?>
-<ZopeData>
-  <record id="1" aka="AAAAAAAAAAE=">
-    <pickle>
-      <global name="Property Existence Constraint" module="erp5.portal_type"/>
-    </pickle>
-    <pickle>
-      <dictionary>
-        <item>
-            <key> <string>constraint_property</string> </key>
-            <value>
-              <tuple>
-                <string>text_content</string>
-              </tuple>
-            </value>
-        </item>
-        <item>
-            <key> <string>description</string> </key>
-            <value> <string>Property text content must be defined</string> </value>
-        </item>
-        <item>
-            <key> <string>id</string> </key>
-            <value> <string>text_content_existence_constraint</string> </value>
-        </item>
-        <item>
-            <key> <string>message_no_such_property</string> </key>
-            <value> <string>XML must be set</string> </value>
-        </item>
-        <item>
-            <key> <string>portal_type</string> </key>
-            <value> <string>Property Existence Constraint</string> </value>
-        </item>
-      </dictionary>
-    </pickle>
-  </record>
-</ZopeData>

master/bt5/vifib_base/PropertySheetTemplateItem/portal_property_sheets/SoftwareInstanceConstraint/text_content_valid_xml_constraint.xml

@@ -32,6 +32,18 @@
             <key> <string>id</string> </key>
             <value> <string>text_content_valid_xml_constraint</string> </value>
         </item>
+        <item>
+            <key> <string>int_index</string> </key>
+            <value>
+              <none/>
+            </value>
+        </item>
+        <item>
+            <key> <string>membership_criterion_category</string> </key>
+            <value>
+              <tuple/>
+            </value>
+        </item>
         <item>
             <key> <string>message_expression_error</string> </key>
             <value> <string>Instance XML is invalid: ${error}</string> </value>
@@ -44,6 +56,22 @@
             <key> <string>portal_type</string> </key>
             <value> <string>TALES Constraint</string> </value>
         </item>
+        <item>
+            <key> <string>string_index</string> </key>
+            <value>
+              <none/>
+            </value>
+        </item>
+        <item>
+            <key> <string>test_method_id</string> </key>
+            <value>
+              <tuple/>
+            </value>
+        </item>
+        <item>
+            <key> <string>test_tales_expression</string> </key>
+            <value> <string>python: context.getTextContent() is not None</string> </value>
+        </item>
       </dictionary>
     </pickle>
   </record>

master/bt5/vifib_base/bt/revision

-407
\ No newline at end of file
+408
\ No newline at end of file