(bug 5506) Make Title::isAlwaysKnown() return true for known special pages and files...

Besides fixing the display of the latter in logs, edit summaries and other places relying on Linker::link(),
the change should allow considerable simplification (not included in this commit) of that function, as
well as of several related functions e.g. in the Parser and Skin classes.  To that end, I've also introduced
a new function Title::isKnown() to wrap the common condition "$title->exists() || $title->isAlwaysKnown()",
and have clarified the roles of the three methods.

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 00fbbd6..52cdcba 100644 (file)
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -399,6 +399,8 @@ The following extensions are migrated into MediaWiki 1.14:
   new pages in the recent changes IRC feed
 * Ugly tooltips in Special:Statistics were phased out in favor of more direct
   information. Went ahead and rewrote SpecialStatistics to subclass SpecialPage
+* (bug 5506) Links to files on foreign repositories are now shown consistently
+  as bluelinks e.g. in logs and edit summaries
 
 === API changes in 1.14 ===
 

diff --git a/includes/Title.php b/includes/Title.php
index 9e52e5a..6544428 100644 (file)
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -3093,7 +3093,12 @@ class Title {
        }
 
        /**
-        * Check if page exists
+        * Check if page exists.  For historical reasons, this function simply
+        * checks for the existence of the title in the page table, and will
+        * thus return false for interwiki links, special pages and the like.
+        * If you want to know if a title can be meaningfully viewed, you should
+        * probably call the isKnown() method instead.
+        *
         * @return \type{\bool} TRUE or FALSE
         */
        public function exists() {
@@ -3101,21 +3106,51 @@ class Title {
        }
 
        /**
-        * Do we know that this title definitely exists, or should we otherwise
-        * consider that it exists?
+        * Should links to this title be shown as potentially viewable (i.e. as
+        * "bluelinks"), even if there's no record by this title in the page
+        * table?
+        *
+        * This function is semi-deprecated for public use, as well as somewhat
+        * misleadingly named.  You probably just want to call isKnown(), which
+        * calls this function internally.
         *
         * @return \type{\bool} TRUE or FALSE
         */
        public function isAlwaysKnown() {
-               // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
-               // the full l10n of that language to be loaded. That takes much memory and
-               // isn't needed. So we strip the language part away.
-               // Also, extension messages which are not loaded, are shown as red, because
-               // we don't call MessageCache::loadAllMessages.
-               list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
-               return $this->isExternal()
-                       || ( $this->mNamespace == NS_MAIN && $this->mDbkeyform == '' )
-                       || ( $this->mNamespace == NS_MEDIAWIKI && wfMsgWeirdKey( $basename ) );
+               if( $this->mInterwiki != '' ) {
+                       return true;  // any interwiki link might be viewable, for all we know
+               }
+               switch( $this->mNamespace ) {                   
+               case NS_MEDIA:
+               case NS_FILE:
+                       return wfFindFile( $this );  // file exists, possibly in a foreign repo
+               case NS_SPECIAL:
+                       return SpecialPage::exists( $this->getDBKey() );  // valid special page
+               case NS_MAIN:
+                       return $this->mDbkeyform == '';  // selflink, possibly with fragment
+               case NS_MEDIAWIKI:
+                       // If the page is form Mediawiki:message/lang, calling wfMsgWeirdKey causes
+                       // the full l10n of that language to be loaded. That takes much memory and
+                       // isn't needed. So we strip the language part away.
+                       // Also, extension messages which are not loaded, are shown as red, because
+                       // we don't call MessageCache::loadAllMessages.
+                       list( $basename, /* rest */ ) = explode( '/', $this->mDbkeyform, 2 );
+                       return wfMsgWeirdKey( $basename );  // known system message
+               default:
+                       return false;
+               }
+       }
+
+       /**
+        * Does this title refer to a page that can (or might) be meaningfully
+        * viewed?  In particular, this function may be used to determine if
+        * links to the title should be rendered as "bluelinks" (as opposed to
+        * "redlinks" to non-existent pages).
+        *
+        * @return \type{\bool} TRUE or FALSE
+        */
+       public function isKnown() {
+               return $this->exists() || $this->isAlwaysKnown();
        }
 
        /**