Fix behavior of label associated with control element

Source/core/html/HTMLLabelElement.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2010 Apple Inc. All rights reserved.
  *           (C) 2006 Alexey Proskuryakov (ap@nypop.com)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 105 matching lines @@
         if (node->isHTMLElement() && toHTMLElement(node)->isInteractiveContent())
             return true;
         node = node->parentOrShadowHostNode();
     }
     return false;
 }
 
 void HTMLLabelElement::defaultEventHandler(Event* evt)
 {
     static bool processingClick = false;
+    static bool isDragged = false;
 
     if (evt->type() == EventTypeNames::click && !processingClick) {
+        // If click event is generated after selecting the text in label
+        // by dragging over it, then do not pass the click event to control
+        // element.
+        if (isDragged) {
+            isDragged = false;

[esprehn, 2014/09/09 20:32:45]

Static vars like this seem pretty sketchy.

+            return;
+        }
+
         // If the click is not simulated and the text of label element is
-        // selected, do not pass the event to control element.
+        // selected, by continous clicking, then save the selection
+        // and pass the click event to control element.
         // Note: a click event may be not a mouse event if created by
         // document.createEvent().
+        VisibleSelection savedSelection;
         if (evt->isMouseEvent() && !toMouseEvent(evt)->isSimulated()) {
             if (LocalFrame* frame = document().frame()) {
-                if (frame->selection().selection().isRange())
-                    return;
+                if (frame->selection().isRange())
+                    savedSelection = frame->selection().selection();
             }
         }
 
-
         RefPtrWillBeRawPtr<HTMLElement> element = control();
 
         // If we can't find a control or if the control received the click
         // event, then there's no need for us to do anything.
         if (!element || (evt->target() && element->containsIncludingShadowDOM(evt->target()->toNode())))
             return;
 
         if (evt->target() && isInInteractiveContent(evt->target()->toNode()))
             return;
 
         processingClick = true;
 
         document().updateLayoutIgnorePendingStylesheets();
         if (element->isMouseFocusable())
             element->focus(true, FocusTypeMouse);
 
         // Click the corresponding control.
         element->dispatchSimulatedClick(evt);
 
+        // Restore the saved selection.
+        if (savedSelection.isRange()) {
+            if (LocalFrame* frame = document().frame())
+                frame->selection().setSelection(savedSelection);
+        }
+
         processingClick = false;
 
         evt->setDefaultHandled();
+    } else if (evt->type() == EventTypeNames::mousemove && evt->isMouseEvent()) {
+        MouseEvent* mouseEvent = toMouseEvent(evt);
+        if (mouseEvent->button() != LeftButton || !mouseEvent->buttonDown())
+            return;
+        // Mark isDragged: true, as selection is started,
+        // by dragging the mouse over label text.
+        isDragged = true;

[esprehn, 2014/09/09 20:32:45]

This doesn't seem like the right way to detect dragging.

     }
 
     HTMLElement::defaultEventHandler(evt);
 }
 
 bool HTMLLabelElement::willRespondToMouseClickEvents()
 {
     if (control() && control()->willRespondToMouseClickEvents())
         return true;
 
@@ skipping 56 matching lines @@
 {
     if (insertionPoint->isInTreeScope() && treeScope() == document()) {
         TreeScope& treeScope = insertionPoint->treeScope();
         if (treeScope.shouldCacheLabelsByForAttribute())
             updateLabel(treeScope, fastGetAttribute(forAttr), nullAtom);
     }
     HTMLElement::removedFrom(insertionPoint);
 }
 
 } // namespace