327606 - Page is not redisplayed when typing [End] key (no repaint after scrolling suddenly)

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Vincent Lefevre]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.0.1) Gecko/20060111 Firefox/1.5.0.1

When I type the [End] key with the URL above, the page is not always redisplayed, and sometimes redisplayed after a few seconds.

Reproducible: Sometimes

Steps to Reproduce:
1. Open the above URL.
2. Make sure the page has the focus (e.g. click on it).
3. Type [End].
Actual Results:  
The scroll bar moves to the bottom as expected (showing that the event has been taken into account), but the displayed page does not change: I still have the top of the document.

Expected Results:  
The bottom of the document should be displayed.

This bug doesn't always occur: the bottom of the document is sometimes displayed immediately. It is sometimes displayed after a few seconds. When I scroll upwards, the new lines are correctly displayed (but the old ones are just shifted downwards -- not surprising).
I couldn't reproduce this bug on any other HTML document. Quitting and restarting Firefox didn't make the bug disappear.

Comment 1

[Vincent Lefevre]

Note: there is no problem with the [Home] key or when scrolling with the mouse or Page Up / Page Down.

Comment 2

[Vincent Lefevre]

After reloading the page, I can no longer reproduce the bug. But the page has changed (the last displayed comment was #259).

Comment 3

[Jesse Ruderman]

I've had this happen (on Mac) on pages whose heights are close to certain powers of 2.  But bug 292914 is marked as fixed...

Comment 4

[Vincent Lefevre]

(In reply to comment #3)
> I've had this happen (on Mac) on pages whose heights are close to certain
> powers of 2.  But bug 292914 is marked as fixed...

I can reproduce the problem on https://bugzilla.mozilla.org/show_bug.cgi?id=76431 and indeed, it occurs only for certain heights, but this doesn't seem to be directly related to powers of 2. For the following window height / viewport height:

1017 / 791 -> no
1024 / 798 -> no
1026 / 800 -> no
1027 / 801 -> no
1028 / 802 -> yes
1030 / 804 -> yes
1032 / 806 -> yes
1059 / 833 -> yes
1104 / 878 -> yes
1140 / 914 -> yes

And similarly, with the same page in another window (with 1 line of tabs instead of 4):
855 / 704 and below -> no
856 / 705 and above -> yes

Comment 5

[Vincent Lefevre]

Also, if I try after decreasing or increasing the text, I can't reproduce the bug (hmm... this may depend on the document height in pixels, as in bug 292914, but I don't know how to get this information -- the Web Developer extension doesn't seem to provide it).

Moreover, if I try to decrease or increase the text (with Cmd- or Cmd+) while the page hasn't been redrawn (i.e. just after [End] with large heights), then Firefox can't redraw anything except the window title when I scroll or switch tabs.

Comment 6

[Jesse Ruderman]

javascript:alert(document.documentElement.offsetHeight)

Comment 7

[Vincent Lefevre]

Attachment: testcase

This test case is based on the one given in bug 292914. It no longer depends on the font size. Here, when the viewport height is >= 624, the page is not redisplayed after [Home] then [End].

Comment 8

[Vincent Lefevre]

The same problem sometimes occurs when clicking on an internal link.

BTW, this bug is still UNCONFIRMED. Could anyone try the testcase?

Comment 9

[Jesse Ruderman]

I can't reproduce the bug using this testcase on trunk.

Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.9a1) Gecko/20060621 Minefield/3.0a1

Comment 10

[Steve England [:stevee]]

Reporter, do you still see this problem with the latest Firefox 2? If not, can you please close this bug as WORKSFORME. Thanks!

Comment 11

[Vincent Lefevre]

(In reply to comment #10)
> Reporter, do you still see this problem with the latest Firefox 2?

Yes, it still occurs with Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8.1.4) Gecko/20070515 Firefox/2.0.0.4.

Comment 12

[u88484]

This bug was reported using a version of Firefox that security and stability updates are no longer provided for.  All users are strongly encouraged to upgrade to Firefox 3 by selecting 'Check for Updates' in the Help menu or by going to http://www.mozilla.com/en-US/firefox/firefox.html

If you can no longer reproduce this bug using the latest Firefox 3.0.x version, please change the status of this bug to 'RESOLVED' 'WORKSFORME'.

If you can still reproduce this bug, please provide additional details to help resolve this issue.

Comment 13

[Vincent Lefevre]

I can no longer reproduce this bug.