Changeset 196264 in webkit

Timestamp:

Feb 8, 2016 11:41:09 AM (8 years ago)

Author:

Carlos Garcia Campos

Message:

Infinite loop when processing mouse events synchronously
​https://bugs.webkit.org/show_bug.cgi?id=153995

Reviewed by Darin Adler.

This happened with WTR in the GTK+ port after landing patch in bug
#153740. The thing is that WTR forces events handling IPC messages
to be synchronous. When a drag and drop operation is in progress,
the web process ignores mouse move events and replies with
DidReceiveEvent signal. The DidReceiveEvent message handler in
WebPageProxy checks if we have a m_nextMouseMoveEvent and handles
it, but when all this happens synchronously the
m_nextMouseMoveEvent is the current one because we haven't
returned yet from handleMouseEvent(). We need to invalidate the
m_nextMouseMoveEvent before calling handleMouseEvent().

• UIProcess/WebPageProxy.cpp:

(WebKit::WebPageProxy::didReceiveEvent):

Location:

trunk/Source/WebKit2

Files:

• ChangeLog (modified) (1 diff)
• UIProcess/WebPageProxy.cpp (modified) (1 diff)

trunk/Source/WebKit2/ChangeLog

@@ +1 @@
+2016-02-08  Carlos Garcia Campos  <cgarcia@igalia.com>
+
+        Infinite loop when processing mouse events synchronously
+        https://bugs.webkit.org/show_bug.cgi?id=153995
+
+        Reviewed by Darin Adler.
+
+        This happened with WTR in the GTK+ port after landing patch in bug
+        #153740. The thing is that WTR forces events handling IPC messages
+        to be synchronous. When a drag and drop operation is in progress,
+        the web process ignores mouse move events and replies with
+        DidReceiveEvent signal. The DidReceiveEvent message handler in
+        WebPageProxy checks if we have a m_nextMouseMoveEvent and handles
+        it, but when all this happens synchronously the
+        m_nextMouseMoveEvent is the current one because we haven't
+        returned yet from handleMouseEvent(). We need to invalidate the
+        m_nextMouseMoveEvent before calling handleMouseEvent().
+
+        * UIProcess/WebPageProxy.cpp:
+        (WebKit::WebPageProxy::didReceiveEvent):
+
 2016-02-08  Jeremy Jones  <jeremyj@apple.com>
 

trunk/Source/WebKit2/UIProcess/WebPageProxy.cpp

@@ -4577 +4577 @@
     case WebEvent::MouseMove:
         m_processingMouseMoveEvent = false;
-        if (m_nextMouseMoveEvent) {
-            handleMouseEvent(*m_nextMouseMoveEvent);
-            m_nextMouseMoveEvent = nullptr;
-        }
+        if (m_nextMouseMoveEvent)
+            handleMouseEvent(*std::exchange(m_nextMouseMoveEvent, nullptr));
         break;
     case WebEvent::MouseDown: