Make load* methods of DifferenceEngine idempotent

[lhc/web/wiklou.git] / includes / diff / DifferenceEngine.php

diff --git a/includes/diff/DifferenceEngine.php b/includes/diff/DifferenceEngine.php
index 1d9ad05..fbc3dd3 100644 (file)
--- a/includes/diff/DifferenceEngine.php
+++ b/includes/diff/DifferenceEngine.php
@@ -36,19 +36,19 @@ class DifferenceEngine extends ContextSource {
         */
        const DIFF_VERSION = '1.12';
 
-       /** @var int */
+       /** @var int Revision ID or 0 for current */
        public $mOldid;
 
-       /** @var int */
+       /** @var int|string Revision ID or null for current or an alias such as 'next' */
        public $mNewid;
 
        private $mOldTags;
        private $mNewTags;
 
-       /** @var Content */
+       /** @var Content|null */
        public $mOldContent;
 
-       /** @var Content */
+       /** @var Content|null */
        public $mNewContent;
 
        /** @var Language */
@@ -60,10 +60,10 @@ class DifferenceEngine extends ContextSource {
        /** @var Title */
        public $mNewPage;
 
-       /** @var Revision */
+       /** @var Revision|null */
        public $mOldRev;
 
-       /** @var Revision */
+       /** @var Revision|null */
        public $mNewRev;
 
        /** @var bool Have the revisions IDs been loaded */
@@ -75,6 +75,13 @@ class DifferenceEngine extends ContextSource {
        /** @var int How many text blobs have been loaded, 0, 1 or 2? */
        public $mTextLoaded = 0;
 
+       /**
+        * Was the content overridden via setContent()?
+        * If the content was overridden, most internal state (e.g. mOldid or mOldRev) should be ignored.
+        * @var bool
+        */
+       protected $isContentOverridden = false;
+
        /** @var bool Was the diff fetched from cache? */
        public $mCacheHit = false;
 
@@ -1341,6 +1348,7 @@ class DifferenceEngine extends ContextSource {
 
                $this->mTextLoaded = 2;
                $this->mRevisionsLoaded = true;
+               $this->isContentOverridden = true;
        }
 
        /**
@@ -1420,11 +1428,11 @@ class DifferenceEngine extends ContextSource {
         * to false. This is impossible via ordinary user input, and is provided for
         * API convenience.
         *
-        * @return bool
+        * @return bool Whether both revisions were loaded successfully.
         */
        public function loadRevisionData() {
                if ( $this->mRevisionsLoaded ) {
-                       return true;
+                       return $this->isContentOverridden || $this->mNewRev && $this->mOldRev;
                }
 
                // Whether it succeeds or fails, we don't want to try again
@@ -1500,11 +1508,11 @@ class DifferenceEngine extends ContextSource {
        /**
         * Load the text of the revisions, as well as revision data.
         *
-        * @return bool
+        * @return bool Whether the content of both revisions could be loaded successfully.
         */
        public function loadText() {
                if ( $this->mTextLoaded == 2 ) {
-                       return true;
+                       return $this->loadRevisionData() && $this->mOldContent && $this->mNewContent;
                }
 
                // Whether it succeeds or fails, we don't want to try again
@@ -1535,11 +1543,11 @@ class DifferenceEngine extends ContextSource {
        /**
         * Load the text of the new revision, not the old one
         *
-        * @return bool
+        * @return bool Whether the content of the new revision could be loaded successfully.
         */
        public function loadNewText() {
                if ( $this->mTextLoaded >= 1 ) {
-                       return true;
+                       return $this->loadRevisionData();
                }
 
                $this->mTextLoaded = 1;