From 164ce2bc63533be463bb8d5d520760e84c03e743 Mon Sep 17 00:00:00 2001
From: Aaron Schulz <aaron@users.mediawiki.org>
Date: Fri, 13 Jan 2012 04:32:28 +0000
Subject: [PATCH] * Distinguish "does not exist" from failure in
 FSFileBackend::doGetFileStat(). * Added clearstatcache() to doConcatenate()
 to make it safe for callers to stat the file. * A few minor comment tweaks.

---
 includes/filerepo/backend/FSFileBackend.php | 33 +++++++++++++++++++--
 includes/filerepo/backend/FileBackend.php   |  6 ++--
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/includes/filerepo/backend/FSFileBackend.php b/includes/filerepo/backend/FSFileBackend.php
index 4654070e6f..fbf101757a 100644
--- a/includes/filerepo/backend/FSFileBackend.php
+++ b/includes/filerepo/backend/FSFileBackend.php
@@ -405,17 +405,19 @@ class FSFileBackend extends FileBackend {
 			return false; // invalid storage path
 		}
 
-		wfSuppressWarnings();
+		$this->trapWarnings();
 		$stat = is_file( $source ) ? stat( $source ) : false; // regular files only
-		wfRestoreWarnings();
+		$hadError = $this->untrapWarnings();
 
 		if ( $stat ) {
 			return array(
 				'mtime' => wfTimestamp( TS_MW, $stat['mtime'] ),
 				'size'  => $stat['size']
 			);
+		} elseif ( !$hadError ) {
+			return false; // file does not exist
 		} else {
-			return false;
+			return null; // failure
 		}
 	}
 
@@ -495,6 +497,31 @@ class FSFileBackend extends FileBackend {
 
 		return $ok;
 	}
+
+	/**
+	 * Suppress E_WARNING errors and track whether any happen
+	 *
+	 * @return void
+	 */
+	protected function trapWarnings() {
+		$this->hadWarningErrors[] = false; // push to stack
+		set_error_handler( array( $this, 'handleWarning' ), E_WARNING );
+	}
+
+	/**
+	 * Unsuppress E_WARNING errors and return true if any happened
+	 *
+	 * @return bool
+	 */
+	protected function untrapWarnings() {
+		restore_error_handler(); // restore previous handler
+		return array_pop( $this->hadWarningErrors ); // pop from stack
+	}
+
+	private function handleWarning() {
+		$this->hadWarningErrors[count( $this->hadWarningErrors ) - 1] = true;
+		return true; // suppress from PHP handler
+	}
 }
 
 /**
diff --git a/includes/filerepo/backend/FileBackend.php b/includes/filerepo/backend/FileBackend.php
index 76025c8b75..7af34efb02 100644
--- a/includes/filerepo/backend/FileBackend.php
+++ b/includes/filerepo/backend/FileBackend.php
@@ -305,9 +305,9 @@ abstract class FileBackendBase {
 	abstract protected function doPrepare( array $params );
 
 	/**
-	 * Take measures to block web access to a directory and
+	 * Take measures to block web access to a storage directory and
 	 * the container it belongs to. FS backends might add .htaccess
-	 * files wheras backends like Swift this might restrict container
+	 * files whereas backends like Swift this might restrict container
 	 * access to backend user that represents end-users in web request.
 	 * This is not guaranteed to actually do anything.
 	 * 
@@ -774,6 +774,8 @@ abstract class FileBackend extends FileBackendBase {
 			return $status;
 		}
 
+		clearstatcache(); // temp file changed
+
 		return $status;
 	}
 
-- 
2.20.1