Title: Simplify use of MWNamespace::getCanonicalName()

The exists() check performs most of what getCanonicalName() will
do a second time. Make the code more simple, DRY, and performant,
by aiming for EAFP instead of LBYL.

Also fixes a potential bug where it was using current namespace
from $this for exists(), but subject namespace (stored as $namespace)
for getCanonicalName().

Change-Id: I11539bde00bf3df3270869f40fbd62083588b50c

diff --git a/includes/Title.php b/includes/Title.php
index 58e6885..b771477 100644 (file)
--- a/includes/Title.php
+++ b/includes/Title.php
@@ -1027,12 +1027,11 @@ class Title implements LinkTarget {
         */
        public function getNsText() {
                if ( $this->isExternal() ) {
-                       // This probably shouldn't even happen,
-                       // but for interwiki transclusion it sometimes does.
-                       // Use the canonical namespaces if possible to try to
-                       // resolve a foreign namespace.
-                       if ( MWNamespace::exists( $this->mNamespace ) ) {
-                               return MWNamespace::getCanonicalName( $this->mNamespace );
+                       // This probably shouldn't even happen, except for interwiki transclusion.
+                       // If possible, use the canonical name for the foreign namespace.
+                       $nsText = MWNamespace::getCanonicalName( $this->mNamespace );
+                       if ( $nsText !== false ) {
+                               return $nsText;
                        }
                }
 
@@ -4795,14 +4794,12 @@ class Title implements LinkTarget {
         */
        public function getNamespaceKey( $prepend = 'nstab-' ) {
                global $wgContLang;
-               // Gets the subject namespace if this title
-               $namespace = MWNamespace::getSubject( $this->getNamespace() );
-               // Checks if canonical namespace name exists for namespace
-               if ( MWNamespace::exists( $this->getNamespace() ) ) {
-                       // Uses canonical namespace name
-                       $namespaceKey = MWNamespace::getCanonicalName( $namespace );
-               } else {
-                       // Uses text of namespace
+               // Gets the subject namespace of this title
+               $subjectNS = MWNamespace::getSubject( $this->getNamespace() );
+               // Prefer canonical namespace name for HTML IDs
+               $namespaceKey = MWNamespace::getCanonicalName( $subjectNS );
+               if ( $namespaceKey === false ) {
+                       // Fallback to localised text
                        $namespaceKey = $this->getSubjectNsText();
                }
                // Makes namespace key lowercase