Only trash post data if the form has not yet been submitted, preventing loss...

Only trash post data if the form has not yet been submitted, preventing loss of form changes on a form error

htdocs/blocktype/lib.php

@@ -247,14 +247,15 @@ class BlockInstance {
                 global $SESSION;
                 $SESSION->add_error_msg(get_string('errorprocessingform'));
             }
-
-            // This is a bit hacky. Because pieforms will take values from 
-            // $_POST before 'defaultvalue's of form elements, we need to nuke 
-            // all of the post values for the form. The situation where this 
-            // becomes relevant is when someone clicks the configure button for 
-            // one block, then immediately configures another block
-            foreach (array_keys($elements) as $name) {
-                unset($_POST[$name]);
+            else {
+                // This is a bit hacky. Because pieforms will take values from 
+                // $_POST before 'defaultvalue's of form elements, we need to nuke 
+                // all of the post values for the form. The situation where this 
+                // becomes relevant is when someone clicks the configure button for 
+                // one block, then immediately configures another block
+                foreach (array_keys($elements) as $name) {
+                    unset($_POST[$name]);
+                }
             }
 
             $content = $pieform->build(false);