Attempt at fixing bug 26370, which seems to be an infinite loop caused by ob_get_level() never going all the way down to 0 no matter how many output buffers we destroy. Use a for loop instead

includes/resourceloader/ResourceLoader.php

@@ -377,7 +377,11 @@ class ResourceLoader {
 				// See also http://bugs.php.net/bug.php?id=51579
 				// To work around this, we tear down all output buffering before
 				// sending the 304.
-				while ( ob_get_level() > 0 ) {
+				// On some setups, ob_get_level() doesn't seem to go down to zero
+				// no matter how often we call ob_get_clean(), so instead of doing
+				// the more intuitive while ( ob_get_level() > 0 ) ob_get_clean();
+				// we have to be safe here and avoid an infinite loop.
+				for ( $i = 0; $i < ob_get_level(); $i++ ) {
 					ob_end_clean();
 				}