Index: includes/filerepo/File.php
===================================================================
--- includes/filerepo/File.php	(revision 32181)
+++ includes/filerepo/File.php	(working copy)
@@ -90,6 +90,30 @@
 	}
 
 	/**
+	 * Convert a filename into a form required by the local filesystem.
+	 *
+	 * @param $utf8name Original filename (in UTF-8)
+	 * @return Encoded filename
+	 * @private
+	 */
+	static function nameToFSCharset( $utf8name ) {
+		global $wgLocalFilesystemCharsetOverride;
+		return $wgLocalFilesystemCharsetOverride ? iconv( 'UTF-8', $wgLocalFilesystemCharsetOverride, $utf8name ) : $utf8name;
+	}
+
+	/**
+	 * Convert a filename from an encoded form.
+	 *
+	 * @param $fsname Encoded filename
+	 * @return Normal filename (in UTF-8)
+	 * @private
+	 */
+	static function nameFromFSCharset( $fsname ) {
+		global $wgLocalFilesystemCharsetOverride;
+		return $wgLocalFilesystemCharsetOverride ? iconv( $wgLocalFilesystemCharsetOverride, 'UTF-8', $fsname ) : $fsname;
+	}
+
+	/**
 	 * Upgrade the database row if there is one
 	 * Called by ImagePage
 	 * STUB
@@ -147,7 +171,7 @@
 		}
 		return $this->url; 
 	}
-	
+
 	/**
 	 * Return a fully-qualified URL to the file.
 	 * Upload URL paths _may or may not_ be fully qualified, so
@@ -433,7 +457,7 @@
 		}
 		$extension = $this->getExtension();
 		list( $thumbExt, $thumbMime ) = $this->handler->getThumbType( $extension, $this->getMimeType() );
-		$thumbName = $this->handler->makeParamString( $params ) . '-' . $this->getName();
+		$thumbName = $this->handler->makeParamString( $params ) . '-' . self::nameToFSCharset( $this->getName() );
 		if ( $thumbExt != $extension ) {
 			$thumbName .= ".$thumbExt";
 		}
@@ -691,7 +715,7 @@
 	 * Get the path of the file relative to the public zone root
 	 */
 	function getRel() {
-		return $this->getHashPath() . $this->getName();
+		return $this->getHashPath() . self::nameToFSCharset( $this->getName() );
 	}
 
 	/**
@@ -746,7 +770,7 @@
 	function getThumbUrl( $suffix = false ) {
 		$path = $this->repo->getZoneUrl('public') . '/thumb/' . $this->getUrlRel();
 		if ( $suffix !== false ) {
-			$path .= '/' . rawurlencode( $suffix );
+			$path .= '/' . rawurlencode( self::nameFromFSCharset( $suffix ) );
 		}
 		return $path;
 	}
Index: includes/DefaultSettings.php
===================================================================
--- includes/DefaultSettings.php	(revision 32181)
+++ includes/DefaultSettings.php	(working copy)
@@ -228,6 +228,14 @@
 /**#@-*/
 
 /**
+ * Character encoding of the local filesystem used to convert charset in names of uploaded files.
+ * null means no charset conversion
+ *
+ * E.g. for Windows, this might be something like $wgLocalFilesystemCharsetOverride = 'CP1250';
+ */
+$wgLocalFilesystemCharsetOverride = null;
+
+/**
  * Allowed title characters -- regex character class
  * Don't change this unless you know what you're doing
  *