macosx/messages: replace deprecated API call with modern blocks-based counterpart

Additionally, fix a leak

modules/gui/macosx/intf.m

@@ -2145,28 +2145,25 @@ unsigned int CocoaKeyToVLC( unichar i_key )
     [saveFolderPanel setCanSelectHiddenExtension: NO];
     [saveFolderPanel setCanCreateDirectories: YES];
     [saveFolderPanel setAllowedFileTypes: [NSArray arrayWithObject:@"rtf"]];
-    [saveFolderPanel beginSheetForDirectory:nil file: [NSString stringWithFormat: _NS("VLC Debug Log (%s).rtf"), VERSION_MESSAGE] modalForWindow: o_msgs_panel modalDelegate:self didEndSelector:@selector(saveDebugLogAsRTF:returnCode:contextInfo:) contextInfo:nil];
-}
-
-- (void)saveDebugLogAsRTF: (NSSavePanel *)sheet returnCode: (int)returnCode contextInfo: (void *)contextInfo
-{
+    [saveFolderPanel setNameFieldStringValue:[NSString stringWithFormat: _NS("VLC Debug Log (%s).rtf"), VERSION_MESSAGE]];
+    [saveFolderPanel beginSheetModalForWindow: o_msgs_panel completionHandler:^(NSInteger returnCode) {
         if( returnCode == NSOKButton )
         {
             NSUInteger count = [o_msg_arr count];
             NSMutableAttributedString * string = [[NSMutableAttributedString alloc] init];
             for (NSUInteger i = 0; i < count; i++)
-        {
                 [string appendAttributedString: [o_msg_arr objectAtIndex: i]];
-        }
 
             NSData *data = [string RTFFromRange:NSMakeRange( 0, [string length] )
                              documentAttributes:[NSDictionary dictionaryWithObject: NSRTFTextDocumentType forKey: NSDocumentTypeDocumentAttribute]];
 
-        if( [data writeToFile: [[sheet URL] path] atomically: YES] == NO )
+            if( [data writeToFile: [[saveFolderPanel URL] path] atomically: YES] == NO )
                 msg_Warn( p_intf, "Error while saving the debug log" );
 
             [string release];
         }
+    }];
+    [saveFolderPanel release];
 }
 
 #pragma mark -