EnhancedChangesList: Don't render headings for empty days

EnhancedChangesList renders an <h4> for every day, but it does so before it starts rendering the changes for that day. If all of the changes for a different day fail to render (due to permissions issues, extension hooks, or whatever) this would result in an empty heading. Instead, render the heading after formatting is complete, so that if all changes for a given day are dropped, the heading is also dropped. Bug: T171078 Change-Id: I8a0c6cbd679976d18d2c2e6e9ac972fb7b294a42

Author: catrope

includes/changes/EnhancedChangesList.php

@@ -102,15 +102,17 @@ public function recentChangesLine( &$rc, $watched = false, $linenumber = null )
 $rc->mAttribs['rc_timestamp'],
 $this->getUser()
 );
+if ( $this->lastdate === '' ) {
+$this->lastdate = $date;
+}
 
 $ret = '';
 
-# If it's a new day, add the headline and flush the cache
-if ( $date != $this->lastdate ) {
-# Process current cache
+# If it's a new day, flush the cache and update $this->lastdate
+if ( $date !== $this->lastdate ) {
+# Process current cache (uses $this->lastdate to generate a heading)
 $ret = $this->recentChangesBlock();
 $this->rc_cache = [];
-$ret .= Xml::element( 'h4', null, $date ) . "\n";
 $this->lastdate = $date;
 }
 
@@ -763,7 +765,11 @@ protected function recentChangesBlock() {
 }
 }
 
-return '<div>' . $blockOut . '</div>';
+if ( $blockOut === '' ) {
+return '';
+}
+// $this->lastdate is kept up to date by recentChangesLine()
+return Xml::element( 'h4', null, $this->lastdate ) . "\n<div>" . $blockOut . '</div>';
 }
 
 /**