checkfunc() set textChanged only on real change

- if #wiki__text (the default DokuWiki editor field) exists, the
checkfunc() checks whether the field content is changed
- if #wiki__text not exists it assumes that on all change and keydown
events the content of the form #dw__editform is changed (give still
false positives.) (for example the Data plugin has none #wiki__text)

lib/scripts/edit.js

@@ -213,6 +213,7 @@ function deleteDraft() {
 /**
  * Activate "not saved" dialog, add draft deletion to page unload,
  * add handlers to monitor changes
+ * Note: textChanged could be set by e.g. html_edit() as well
  *
  * Sets focus to the editbox as well
  */
@@ -234,19 +235,26 @@ jQuery(function () {
         sel.end   = 0;
         DWsetSelection(sel);
         $edit_text.focus();
+
+        var edit_text_content = $edit_text.val();
     }
 
     var checkfunc = function() {
-        textChanged = true; //global var
+        //global var textChanged
+        if ($edit_text.length > 0) {
+            textChanged = edit_text_content != $edit_text.val();
+        } else {
+            textChanged = true;
+        }
+
         summaryCheck();
     };
 
     $editform.change(checkfunc);
     $editform.keydown(checkfunc);
 
-    var edit_text_content = $edit_text.val();
     window.onbeforeunload = function(){
-        if(window.textChanged && edit_text_content != $edit_text.val()) {
+        if(window.textChanged) {
             return LANG.notsavedyet;
         }
     };