8565 - [PP]painting twice, second time incorrectly

Status: VERIFIED DUPLICATE of bug 10077

(Core Graveyard :: GFX, defect, P3)

Description

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

This may be Linux-only (I haven't tested on other platforms).  It occurs on
1999-06-19-08-M7 from mozilla.org, in both apprunner and viewer.

Every time I do PgUp/PgDn or uparrow/downarrow on a long page (longer than a
screen), I see the page repaint twice.  For example, on
http://www.fas.harvard.edu/~dbaron/links/WPhiladelphia
I see the page, and then a flash back to the gray background, and then the page
comes up again.

I *think* (but am not sure) that this is the cause of a second problem:  that
when there is only half a page left, things display strangely (screenshot to be
attached) - the wrong thing gets displayed in the part of the page that was on
the screen before (things seem to be "moved" twice).  I *think* that it is
painting correctly on the first flash, and incorrectly on the second (but my
vision isn't really sharp enough to be sure).  A way to test this for sure would
be to run apprunner or viewer on a remote computer connected via a modem, using
the local X display.

Comment 1

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: Screenshot after doing PgDn to the bottom (last piece was half-page)

Comment 2

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: Screenshot after doing PgUp to the top (last piece was half-page)

Comment 3

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: Screenshot after hitting down arrow a few times after second screenshot

Comment 4

[Sam Allen]

This seems like a dup of bug 6014.

Comment 5

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Yes, but I think the painting twice may explain bug 6014 - if things are being
moved from one part of the screen to another.

Comment 6

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Attachment: Document with which I confirmed that first paint is correct and second paint is wrong

Comment 7

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

To use attachment 463 [details]:

1) scroll to very bottom of document - note where red stripe is
2) scroll up so red stripe is at bottom
3) Hit PgDn, and notice red flash at spot noted in 1.  Covering all other areas
of the screen with a sheet of paper may help to see this.

This shows the first paint is correct, and the second paint is causing the
errors.

Comment 8

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

Marking [PP] since this seems Linux-only.  Correct me if I'm wrong.

Comment 9

[Patrick C. Beard]

Ramiro, since this is linux-specific (doesn't happen on Windows or Mac) I'm
reassigning to you.

Comment 10

[David Baron :dbaron: (⌚️UTC-5, no longer working on Mozilla)]

See also bug 7354.

Comment 11

[leger]

*** Bug 10078 has been marked as a duplicate of this bug. ***

Comment 12

[ramiro]

David,

Thanks for the report, it was helpful.  Ive just checked in a fix for this.

So im marking this bug dup of bug 10077 (which i just fixed)



*** This bug has been marked as a duplicate of 10077 ***

Comment 13

[Chris Petersen]

Based on the comments, marking as verified duplicate.