More sensible behavior when special page aliases conflict
authorBrad Jorsch <bjorsch@wikimedia.org>
Fri, 19 Sep 2014 18:32:43 +0000 (14:32 -0400)
committerNikerabbit <niklas.laxstrom@gmail.com>
Thu, 25 Sep 2014 07:57:01 +0000 (07:57 +0000)
Right now, SpecialPageFactory::getAliasListObject() just chooses the
last-seen alias and allows any alias to completely override the page's
"canonical" name (from SpecialPageFactory::$list or $wgSpecialPages).
Although the latter doesn't come up often since (almost?) all special pages
have their canonical name as one of their English-language aliases.

More sensible behavior is to always prefer the "canonical" name over any
conflicting aliases, and to prefer an alias that's the first alias for a
special page over one that is a fallback.

Also, when a special page's first alias winds up not actually referring
to that special page, we MUST NOT go redirecting other names for that
special page to that wrong alias.

Bug: 70686
Change-Id: I4b17ec0fdc87b4b0d7ae9d9eea7ffacb54dd6891

includes/specialpage/SpecialPageFactory.php
languages/Language.php
tests/phpunit/includes/specialpage/SpecialPageFactoryTest.php

index 48bcb77..7904140 100644 (file)
@@ -262,10 +262,9 @@ class SpecialPageFactory {
 
        /**
         * Initialise and return the list of special page aliases.  Returns an object with
-        * properties which can be accessed $obj->pagename - each property is an array of
-        * aliases; the first in the array is the canonical alias.  All registered special
-        * pages are guaranteed to have a property entry, and for that property array to
-        * contain at least one entry (English fallbacks will be added if necessary).
+        * properties which can be accessed $obj->pagename - each property name is an
+        * alias, with the value being the canonical name of the special page. All
+        * registered special pages are guaranteed to map to themselves.
         * @return object
         */
        private static function getAliasListObject() {
@@ -273,21 +272,44 @@ class SpecialPageFactory {
                        global $wgContLang;
                        $aliases = $wgContLang->getSpecialPageAliases();
 
-                       $missingPages = self::getPageList();
-
                        self::$aliases = array();
+                       $keepAlias = array();
+
+                       // Force every canonical name to be an alias for itself.
+                       foreach ( self::getPageList() as $name => $stuff ) {
+                               $caseFoldedAlias = $wgContLang->caseFold( $name );
+                               self::$aliases[$caseFoldedAlias] = $name;
+                               $keepAlias[$caseFoldedAlias] = 'canonical';
+                       }
+
                        // Check for $aliases being an array since Language::getSpecialPageAliases can return null
                        if ( is_array( $aliases ) ) {
                                foreach ( $aliases as $realName => $aliasList ) {
-                                       foreach ( $aliasList as $alias ) {
-                                               self::$aliases[$wgContLang->caseFold( $alias )] = $realName;
+                                       $aliasList = array_values( $aliasList );
+                                       foreach ( $aliasList as $i => $alias ) {
+                                               $caseFoldedAlias = $wgContLang->caseFold( $alias );
+
+                                               if ( isset( self::$aliases[$caseFoldedAlias] ) &&
+                                                       $realName === self::$aliases[$caseFoldedAlias]
+                                               ) {
+                                                       // Ignore same-realName conflicts
+                                                       continue;
+                                               }
+
+                                               if ( !isset( $keepAlias[$caseFoldedAlias] ) ) {
+                                                       self::$aliases[$caseFoldedAlias] = $realName;
+                                                       if ( !$i ) {
+                                                               $keepAlias[$caseFoldedAlias] = 'first';
+                                                       }
+                                               } elseif ( !$i ) {
+                                                       wfWarn( "First alias '$alias' for $realName conflicts with " .
+                                                               "{$keepAlias[$caseFoldedAlias]} alias for " .
+                                                               self::$aliases[$caseFoldedAlias]
+                                                       );
+                                               }
                                        }
-                                       unset( $missingPages->$realName );
                                }
                        }
-                       foreach ( $missingPages as $name => $stuff ) {
-                               self::$aliases[$wgContLang->caseFold( $name )] = $name;
-                       }
 
                        // Cast to object: func()[$key] doesn't work, but func()->$key does
                        self::$aliases = (object)self::$aliases;
@@ -620,29 +642,42 @@ class SpecialPageFactory {
        public static function getLocalNameFor( $name, $subpage = false ) {
                global $wgContLang;
                $aliases = $wgContLang->getSpecialPageAliases();
+               $aliasList = self::getAliasListObject();
 
-               if ( isset( $aliases[$name][0] ) ) {
-                       $name = $aliases[$name][0];
-               } else {
-                       // Try harder in case someone misspelled the correct casing
+               // Find the first alias that maps back to $name
+               if ( isset( $aliases[$name] ) ) {
                        $found = false;
-                       // Check for $aliases being an array since Language::getSpecialPageAliases can return null
+                       foreach ( $aliases[$name] as $alias ) {
+                               $caseFoldedAlias = $wgContLang->caseFold( $alias );
+                               $caseFoldedAlias = str_replace( ' ', '_', $caseFoldedAlias );
+                               if ( isset( $aliasList->$caseFoldedAlias ) &&
+                                       $aliasList->$caseFoldedAlias === $name
+                               ) {
+                                       $name = $alias;
+                                       $found = true;
+                                       break;
+                               }
+                       }
+                       if ( !$found ) {
+                               wfWarn( "Did not find a usable alias for special page '$name'. " .
+                                       "It seems all defined aliases conflict?" );
+                       }
+               } else {
+                       // Check if someone misspelled the correct casing
                        if ( is_array( $aliases ) ) {
                                foreach ( $aliases as $n => $values ) {
                                        if ( strcasecmp( $name, $n ) === 0 ) {
                                                wfWarn( "Found alias defined for $n when searching for " .
                                                        "special page aliases for $name. Case mismatch?" );
-                                               $name = $values[0];
-                                               $found = true;
-                                               break;
+                                               return self::getLocalNameFor( $n, $subpage );
                                        }
                                }
                        }
-                       if ( !$found ) {
-                               wfWarn( "Did not find alias for special page '$name'. " .
-                                       "Perhaps no aliases are defined for it?" );
-                       }
+
+                       wfWarn( "Did not find alias for special page '$name'. " .
+                               "Perhaps no aliases are defined for it?" );
                }
+
                if ( $subpage !== false && !is_null( $subpage ) ) {
                        $name = "$name/$subpage";
                }
index bf2e3a3..b985077 100644 (file)
@@ -737,6 +737,8 @@ class Language {
        }
 
        /**
+        * @deprecated since 1.24, doesn't handle conflicting aliases. Use
+        *   SpecialPageFactory::getLocalNameFor instead.
         * @param string $name
         * @return string
         */
index d56ecad..4619c2e 100644 (file)
  */
 class SpecialPageFactoryTest extends MediaWikiTestCase {
 
+       protected function tearDown() {
+               parent::tearDown();
+
+               SpecialPageFactory::resetList();
+       }
+
        public function newSpecialAllPages() {
                return new SpecialAllPages();
        }
@@ -42,7 +48,6 @@ class SpecialPageFactoryTest extends MediaWikiTestCase {
         */
        public function testGetPage( $spec, $shouldReuseInstance ) {
                $this->mergeMwGlobalArrayValue( 'wgSpecialPages', array( 'testdummy' => $spec ) );
-
                SpecialPageFactory::resetList();
 
                $page = SpecialPageFactory::getPage( 'testdummy' );
@@ -50,8 +55,6 @@ class SpecialPageFactoryTest extends MediaWikiTestCase {
 
                $page2 = SpecialPageFactory::getPage( 'testdummy' );
                $this->assertEquals( $shouldReuseInstance, $page2 === $page, "Should re-use instance:" );
-
-               SpecialPageFactory::resetList();
        }
 
        /**
@@ -59,12 +62,11 @@ class SpecialPageFactoryTest extends MediaWikiTestCase {
         */
        public function testGetNames() {
                $this->mergeMwGlobalArrayValue( 'wgSpecialPages', array( 'testdummy' => 'SpecialAllPages' ) );
-
                SpecialPageFactory::resetList();
+
                $names = SpecialPageFactory::getNames();
                $this->assertInternalType( 'array', $names );
                $this->assertContains( 'testdummy', $names );
-               SpecialPageFactory::resetList();
        }
 
        /**
@@ -72,14 +74,11 @@ class SpecialPageFactoryTest extends MediaWikiTestCase {
         */
        public function testResolveAlias() {
                $this->setMwGlobals( 'wgContLang', Language::factory( 'de' ) );
-
                SpecialPageFactory::resetList();
 
                list( $name, $param ) = SpecialPageFactory::resolveAlias( 'Spezialseiten/Foo' );
                $this->assertEquals( 'Specialpages', $name );
                $this->assertEquals( 'Foo', $param );
-
-               SpecialPageFactory::resetList();
        }
 
        /**
@@ -87,13 +86,10 @@ class SpecialPageFactoryTest extends MediaWikiTestCase {
         */
        public function testGetLocalNameFor() {
                $this->setMwGlobals( 'wgContLang', Language::factory( 'de' ) );
-
                SpecialPageFactory::resetList();
 
                $name = SpecialPageFactory::getLocalNameFor( 'Specialpages', 'Foo' );
                $this->assertEquals( 'Spezialseiten/Foo', $name );
-
-               SpecialPageFactory::resetList();
        }
 
        /**
@@ -101,14 +97,142 @@ class SpecialPageFactoryTest extends MediaWikiTestCase {
         */
        public function testGetTitleForAlias() {
                $this->setMwGlobals( 'wgContLang', Language::factory( 'de' ) );
-
                SpecialPageFactory::resetList();
 
                $title = SpecialPageFactory::getTitleForAlias( 'Specialpages/Foo' );
                $this->assertEquals( 'Spezialseiten/Foo', $title->getText() );
                $this->assertEquals( NS_SPECIAL, $title->getNamespace() );
+       }
 
+       /**
+        * @dataProvider provideTestConflictResolution
+        */
+       public function testConflictResolution(
+               $test, $aliasesList, $alias, $expectedName, $expectedAlias, $expectWarnings
+       ) {
+               global $wgContLang;
+               $lang = clone $wgContLang;
+               $lang->mExtendedSpecialPageAliases = $aliasesList;
+               $this->setMwGlobals( 'wgContLang', $lang );
+               $this->setMwGlobals( 'wgSpecialPages',
+                       array_combine( array_keys( $aliasesList ), array_keys( $aliasesList ) )
+               );
                SpecialPageFactory::resetList();
+
+               // Catch the warnings we expect to be raised
+               $warnings = array();
+               $this->setMwGlobals( 'wgDevelopmentWarnings', true );
+               set_error_handler( function ( $errno, $errstr ) use ( &$warnings ) {
+                       if ( preg_match( '/First alias \'[^\']*\' for .*/', $errstr ) ||
+                               preg_match( '/Did not find a usable alias for special page .*/', $errstr )
+                       ) {
+                               $warnings[] = $errstr;
+                               return true;
+                       }
+                       return false;
+               } );
+               $reset = new ScopedCallback( 'restore_error_handler' );
+
+               list( $name, /*...*/ ) = SpecialPageFactory::resolveAlias( $alias );
+               $this->assertEquals( $expectedName, $name, "$test: Alias to name" );
+               $result = SpecialPageFactory::getLocalNameFor( $name );
+               $this->assertEquals( $expectedAlias, $result, "$test: Alias to name to alias" );
+
+               $gotWarnings = count( $warnings );
+               if ( $gotWarnings !== $expectWarnings ) {
+                       $this->fail( "Expected $expectWarnings warning(s), but got $gotWarnings:\n" .
+                               join( "\n", $warnings )
+                       );
+               }
+       }
+
+       /**
+        * @dataProvider provideTestConflictResolution
+        */
+       public function testConflictResolutionReversed(
+               $test, $aliasesList, $alias, $expectedName, $expectedAlias, $expectWarnings
+       ) {
+               // Make sure order doesn't matter by reversing the list
+               $aliasesList = array_reverse( $aliasesList );
+               return $this->testConflictResolution(
+                       $test, $aliasesList, $alias, $expectedName, $expectedAlias, $expectWarnings
+               );
+       }
+
+       public function provideTestConflictResolution() {
+               return array(
+                       array(
+                               'Canonical name wins',
+                               array( 'Foo' => array( 'Foo', 'Bar' ), 'Baz' => array( 'Foo', 'BazPage', 'Baz2' ) ),
+                               'Foo',
+                               'Foo',
+                               'Foo',
+                               1,
+                       ),
+
+                       array(
+                               'Doesn\'t redirect to a different special page\'s canonical name',
+                               array( 'Foo' => array( 'Foo', 'Bar' ), 'Baz' => array( 'Foo', 'BazPage', 'Baz2' ) ),
+                               'Baz',
+                               'Baz',
+                               'BazPage',
+                               1,
+                       ),
+
+                       array(
+                               'Canonical name wins even if not aliased',
+                               array( 'Foo' => array( 'FooPage' ), 'Baz' => array( 'Foo', 'BazPage', 'Baz2' ) ),
+                               'Foo',
+                               'Foo',
+                               'FooPage',
+                               1,
+                       ),
+
+                       array(
+                               'Doesn\'t redirect to a different special page\'s canonical name even if not aliased',
+                               array( 'Foo' => array( 'FooPage' ), 'Baz' => array( 'Foo', 'BazPage', 'Baz2' ) ),
+                               'Baz',
+                               'Baz',
+                               'BazPage',
+                               1,
+                       ),
+
+                       array(
+                               'First local name beats non-first',
+                               array( 'First' => array( 'Foo' ), 'NonFirst' => array( 'Bar', 'Foo' ) ),
+                               'Foo',
+                               'First',
+                               'Foo',
+                               0,
+                       ),
+
+                       array(
+                               'Doesn\'t redirect to a different special page\'s first alias',
+                               array(
+                                       'Foo' => array( 'Foo' ),
+                                       'First' => array( 'Bar' ),
+                                       'Baz' => array( 'Foo', 'Bar', 'BazPage', 'Baz2' )
+                               ),
+                               'Baz',
+                               'Baz',
+                               'BazPage',
+                               1,
+                       ),
+
+                       array(
+                               'Doesn\'t redirect wrong even if all aliases conflict',
+                               array(
+                                       'Foo' => array( 'Foo' ),
+                                       'First' => array( 'Bar' ),
+                                       'Baz' => array( 'Foo', 'Bar' )
+                               ),
+                               'Baz',
+                               'Baz',
+                               'Baz',
+                               2,
+                       ),
+
+               );
        }
 
 }