404702 - Can end up with a stale translucent drag feedback image in this case

Status: REOPENED

(Core :: DOM: Copy & Paste and Drag & Drop, defect)

Description

[Martijn Wargers (dead)]

This can be a bit difficult to reproduce, I'm afraid, it might be easier to reproduce in a debug build, not sure.

Load the testcase from the url (from bug 382444), then drag a local file over the browser, wait a little while, then release your left mouse button. Sometimes, the translucent drag feedback image doesn't disappear.
(as an alternative to releasing the left mouse button, you can do a right-click, this cancels the drag, but doesn't load the dragged file)

Comment 1

[Dão Gottwald [:dao]]

I've seen this using "musikCube", so maybe it's a Windows bug.

Comment 2

[Jonathan Haas]

This is reproduceable. You can reproduce it by loading this testcase: https://bugzilla.mozilla.org/attachment.cgi?id=266610 , dragging a local file oder the page and releasing the left mouse button/clicking the right mouse button during the refresh when there appears a no-drop cursor for a very short time.

If it does not work try a different file or restart firefox.

Comment 3

[Jonathan Haas]

Attachment: Testcase

You can also use this testcase. It's easier to reproduce.

Steps to reproduce:
- Load testcase
- Be fast, drag a file over the iframe while it says "server not found", do not release the left mousebutton.
- When the cursor changes to a no-drop-cursor click the right mouse button (while the left mouse button is still pressed. Be fast.
- Release both mouse buttons

This bug is reproduceable everytime for me using this method.

Comment 4

[Jonathan Haas]

And it does not happen only with files. You can reproduce this also by dragging text from another (trunk) firefox/thunderbird process instead of the file.

Notice that the drag feedback goes away when you start dragging für example some text in the firefox window or when you drag another file over the window.

Comment 5

[Jim Mathies [:jimm]]

This doesn't appear to be related to bug 374593, as I can reproduce it in version post and prior to that patch landing. The browser is getting caught up in what looks like some sort of layout loop problem. 

As soon as I start dragging an object near firefox's main window the console starts to dump a ton of debug data that looks like this -

nsLineLayout: Text(17)@094D5930 metrics=1720320,1140!
nsLineLayout: Text(18)@094D5970 metrics=1720320,1140!
nsLineLayout: Text(19)@094D59B0 metrics=1720320,1140!
nsLineLayout: Text(20)@094D59F0 metrics=1720320,1140!
..

Then the browser freezes. I also tested the nightly the day before 374593 got checked in, it was freezing as well and was displaying "aaaaaaaaaaa..." in the iframe. (attached)

Comment 6

[Jim Mathies [:jimm]]

Attachment: 11-15 nightly freeze screenshot

Comment 7

[Jonathan Haas]

Attachment: better testcase

The aaa... and the high cpu load are more or less intended and are not the bug. This bug is about the not disappearing drag feedback.

I've attached a better, not hanging, testcase.

Comment 8

[Jonathan Haas]

Attachment: better testcase v1.1

oops, there was a small error in the testcase.

Comment 9

[Jim Mathies [:jimm]]

Mozilla/5.0 (Windows NT 6.1; WOW64; rv:12.0a1) Gecko/20120105 Firefox/12.0a1

This appears to be WFM in a latest nightly. Can someone tuned in confirm?