624127 - mouse movement changes selected text even when no key or mouse key is pressed

Status: RESOLVED FIXED

(Core :: DOM: UI Events & Focus Handling, defect)

Description

[Stefan]

User-Agent:       
Build Identifier: Mozilla/5.0 (X11; Linux x86_64; rv:2.0b9pre) Gecko/20100101 Firefox/4.0b9pre

Mouse movements without keys pressed modify the current text selection as if the left mouse button is still pressed.

Reproducible: Always

Steps to Reproduce:
1. clear cookies, load www.youtube.com
   -> box (light blue background) with "Welcome to YouTube! Suggested 
      Location Filte..." appears
2. Place mouse cursor in front of "W" in "Welcome".
3. Click and hold left mouse button until step 5
4. Move (mark) downwards until mouse is in the advertisement image
   -> text in box is selected
5. release left mouse button.
6. slowly move mouse up
Actual Results:  
Selection shrinks as if left mouse button is still pressed.

Expected Results:  
Keep selection after releasing left mouse button.

Comment 1

[Stefan]

Built from http://hg.mozilla.org/mozilla-central/rev/df3c1150dd7a

Comment 2

[Alice0775 White]

Regression window:
Works:
http://hg.mozilla.org/mozilla-central/rev/bf0fdec8f43b
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.3a1pre) Gecko/20090913 Minefield/3.7a1pre ID:20090913032541
Fails:
http://hg.mozilla.org/mozilla-central/rev/912c6ae3b70c
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.3a1pre) Gecko/20090914 Minefield/3.7a1pre ID:20090914031022
Pushlog:
http://hg.mozilla.org/mozilla-central/pushloghtml?fromchange=bf0fdec8f43b&tochange=912c6ae3b70c

In local build,
build from eda2433181c9 : Fails
build from 8afb65205203 : works

Regressed by:
eda2433181c9	Neil Deakin — Bug 503943, add mouse capturing api to elements, remove capturing from views, r=roc,sr=smaug

Comment 3

[Johnny Stenback (:jst)]

Blocking, but .x. I don't think we absolutely have to fix this for 2.0. Over to Neil as this appears to be a regression from his changes.

Comment 4

[Neil Deakin]

Need a testcase, or at least some steps to reproduce that aren't dependent on what youtube website looks like. (There is no text 'Welcome to YouTube!...' when I view it)

Comment 5

[Stefan]

Attachment: testcase

Comment 6

[Stefan]

STR:

1. click and hold before the "N" in the first line
2. drag into the iframe
3. release button
4. move to second line

Comment 7

[Stefan]

Attachment: testcase

Comment 8

[Neil Deakin]

This is caused because SetMouseDownState(PR_TRUE) is called on the parent presshell when the mouse is pressed, and on SetMouseDownState(PR_FALSE) the child frame's presshell when the mouse is released.

So SetMouseDownState(PR_FALSE) will need to be retargeted to the right presshell.

Comment 9

[Neil Deakin]

Attachment: possible patch

This demonstrates a fix, but it probably isn't the right place to clear the mousedown state.

Comment 10

[Neil Deakin]

Attachment: better patch

Comment 11

[Robert O'Callahan (:roc) (email my personal email if necessary)]

     frameSelection->SetMouseDownState(PR_FALSE);
     frameSelection->StopAutoScrollTimer();
   }
 
+  if (captureContent) {
+    nsIDocument* doc = captureContent->GetCurrentDoc();
+    if (doc) {
+      nsIPresShell* capturingShell = doc->GetShell();
+      if (capturingShell && capturingShell != PresContext()->GetPresShell()) {
+        nsCOMPtr<nsFrameSelection> frameSelection = capturingShell->FrameSelection();
+        frameSelection->SetMouseDownState(PR_FALSE);
+        frameSelection->StopAutoScrollTimer();

Can we restructure things a little bit so we only have one call to SetMouseDownState and StopAutoScrollTimer?

Comment 12

[Neil Deakin]

Attachment: updated for comments

Comment 13

[(no longer active)]

http://hg.mozilla.org/mozilla-central/rev/f1f0bf6fedbb