412352 - Inconsistent layout with <input type="file">, position:absolute

Status: RESOLVED WORKSFORME

(Core :: Layout: Form Controls, defect)

Description

[Jesse Ruderman]

Testcase 1 (identical to layout/forms/crashtests/386554-1.html) demonstrates a subtle difference in dynamic vs. static rendering: the anti-aliasing pixels are cut off in the testcase but not in the reference.

Testcase 2 makes the problem more clear using a border: the width of the div is different by several pixels.

Comment 1

[Jesse Ruderman]

Attachment: testcase 1

Comment 2

[Jesse Ruderman]

Attachment: reference 1

Comment 3

[Jesse Ruderman]

Attachment: testcase 2

Comment 4

[Jesse Ruderman]

Attachment: reference 2

Comment 5

[Jesse Ruderman]

> identical to layout/forms/crashtests/386554-1.html

Oops, not quite identical.  I removed a "top: 100%".

Comment 6

[Boris Zbarsky [:bzbarsky]]

Is this a regression?  Or Mac-only?  I can't reproduce in a 2007-11-27-02 Seamonkey build on Linux.

Comment 7

[Jesse Ruderman]

I can reproduce with testcase 2 / reference 2 in a 2007-11-11 Firefox build on Mac.  So I guess it's Mac-only.

Comment 8

[Boris Zbarsky [:bzbarsky]]

Does the problem go away if you set -moz-appearance:none on the file input?

Comment 9

[Jesse Ruderman]

Setting "-moz-appearance: none" has no effect on the appearance of file upload controls and does not make this bug go away.

Comment 10

[Boris Zbarsky [:bzbarsky]]

Yeah, I can reproduce on Mac but definitely not on Linux.  Any incremental reflow (e.g. opening the findbar) makes the testcase look like the reference.

Comment 11

[Boris Zbarsky [:bzbarsky]]

So... the frame geometry per se is the same between the two testcases.  The overflow areas, however, are different.  In particular, the overflow rect width of the button is different by 5px or so.

I'm not quite sure why there are these random overflow rects all over this testcase, to be honest (e.g., why does the text input have 4px horizontal overflow to the left?).  But that 5px difference in the overflow rect is what causes the different rendering here.

roc, any idea what's up?

Comment 12

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

Nope. I don't think this is going to block 1.9 though...

Comment 13

[Jesse Ruderman]

WFM, Mac trunk debug.