Reverted r84357 and r90461 and fixed the bug in a better way: in an empty document...

diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index e168eca..6ff1e44 100644 (file)
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -5291,12 +5291,14 @@ class Parser {
         * pull the given section along with its lower-level subsections. If the section is
         * not found, $mode=get will return $newtext, and $mode=replace will return $text.
         *
+        * Section 0 is always considered to exist, even if it only contains the empty
+        * string. If $text is the empty string and section 0 is replaced, $newText is 
+        * returned.
+        *
         * @param $mode String: one of "get" or "replace"
         * @param $newText String: replacement text for section data.
         * @return String: for "get", the extracted section text.
         *                 for "replace", the whole page with the section replaced.
-        *                 If the page is empty and section 0 is requested, $text (as '')
-        *                  is returned
         */
        private function extractSections( $text, $section, $mode, $newText='' ) {
                global $wgTitle; # not generally used but removes an ugly failure mode
@@ -5313,6 +5315,25 @@ class Parser {
                                $flags |= self::PTD_FOR_INCLUSION;
                        }
                }
+
+               # Check for empty input
+               if ( strval( $text ) === '' ) {
+                       # Only sections 0 and T-0 exist in an empty document
+                       if ( $sectionIndex == 0 ) {
+                               if ( $mode === 'get' ) {
+                                       return '';
+                               } else {
+                                       return $newText;
+                               }
+                       } else {
+                               if ( $mode === 'get' ) {
+                                       return $newText;
+                               } else {
+                                       return $text;
+                               }
+                       }
+               }
+
                # Preprocess the text
                $root = $this->preprocessToDom( $text, $flags );
 
@@ -5324,10 +5345,6 @@ class Parser {
                if ( $sectionIndex == 0 ) {
                        # Section zero doesn't nest, level=big
                        $targetLevel = 1000;
-                       if ( !$node ) {
-                               # The page definitely exists - we checked that earlier - so it must be blank: see bug #14005
-                               return $text;
-                       }
                } else {
                        while ( $node ) {
                                if ( $node->getName() === 'h' ) {
@@ -5410,7 +5427,8 @@ class Parser {
 
        /**
         * This function returns $oldtext after the content of the section
-        * specified by $section has been replaced with $text.
+        * specified by $section has been replaced with $text. If the target 
+        * section does not exist, $oldtext is returned unchanged.
         *
         * @param $oldtext String: former text of the article
         * @param $section Numeric: section identifier