Add more logging to track down the source of mysterious drags. Seems they're...

Add more logging to track down the source of mysterious drags. Seems they're not being started through the expected code path that takes minimum distance into account.

ThirdParty/PSMTabBarControl/source/PSMTabBarControl.m

@@ -1386,6 +1386,13 @@ const NSInteger kPSMStartResizeAnimation = 0;
 }
 #pragma mark NSDraggingSource
+
+- (NSDraggingSession *)beginDraggingSessionWithItems:(NSArray<NSDraggingItem *> *)items event:(NSEvent *)event source:(id<NSDraggingSource>)source {
+    ILog(@"Begin dragging tab bar control %p with event %@ source from\n%@",
+         self, event, [NSThread callStackSymbols]);
+    return [super beginDraggingSessionWithItems:items event:event source:source];
+}
+
 - (NSDragOperation)draggingSourceOperationMaskForLocal:(BOOL)isLocal
 {
     return (isLocal ? NSDragOperationMove : NSDragOperationNone);

ThirdParty/PSMTabBarControl/source/PSMTabDragAssistant.m

@@ -169,6 +169,7 @@
     NSDraggingItem *dragItem = [[[NSDraggingItem alloc] initWithPasteboardWriter:pbItem] autorelease];
     [dragItem setDraggingFrame:draggingRect contents:imageToDrag];
+    ILog(@"Begin dragging session for tab bar %p", control);
     NSDraggingSession *draggingSession = [control beginDraggingSessionWithItems:@[ dragItem ]
                                                                           event:event
                                                                          source:control];