(bug 15248) Normalize NBSP and other odd Unicode whitespace characters to normal spaces.

Note: run cleanupTitles.php and cleanupImages.php after deploying this!

RELEASE-NOTES

@@ -415,6 +415,9 @@ this. Was used when mwEmbed was going to be an extension.
   versions of MediaWiki were affected).
 * (bug 14817) Moving a page to a subpage of itself moves it twice
 * (bug 20289) $wgMaximumMovedPages should only count pages actually moved
+* (bug 15248) Non-breaking spaces and certain other Unicode space characters
+  are now normalized to ordinary spaces in titles; if your wiki has existing
+  titles with such characters, run cleanupTitles.php and/or cleanupImages.php
 
 == API changes in 1.16 ==
 

includes/Title.php

@@ -2242,7 +2242,7 @@ class Title {
 
 		# Clean up whitespace
 		#
-		$dbkey = preg_replace( '/[ _]+/', '_', $dbkey );
+		$dbkey = preg_replace( '/[ _\xA0\x{1680}\x{180E}\x{2000}-\x{200B}\x{2028}\x{2029}\x{202F}\x{205F}\x{3000}]+/u', '_', $dbkey );
 		$dbkey = trim( $dbkey, '_' );
 
 		if ( '' == $dbkey ) {