225429 - {inc} BODY[position:abolute] + child element[position:absolute; bottom: 0] :: overlap

Status: RESOLVED FIXED

(Core :: Layout: Positioned, defect)

Description

[Gyuris Gellért]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.6a) Gecko/20031030
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.6a) Gecko/20031030

the elements overlap

Reproducible: Always

Steps to Reproduce:
1. Open the attached file.
2. Resize the bowser's window to such a big size when the 'frame' and 'footer'
do not to reach each other. (This requires high resolution)
3. Switch on the 'last element' by the button below.
-If it is necessary then the 'last element' pushes down the 'footer'. This is
the expected behaviour.
4. Switch off the 'last element'.
5. Resize the browser's window to so small size when the 'frame' and 'footer' do
reach each other. In this case the vertical scrollbar appears.
6. Switch on the 'last element'
- Symptom: the elements overlap, the 'footer' remains there which seems to be
unexpected behaviour.
7. Resize the window in horizontal direction just for one or two pixels.
- The 'footer' gets to its intended position.
8. Switch off the 'last element'
9. Resize the window vertically again.
- 'footer' gets back to its proper position.

Our question is about this symptom. Is this a bug or feature?

Comment 1

[Gyuris Gellért]

Attachment: bug

Comment 2

[Mats Palmgren (inactive)]

Confirming bug, 2003-11-10-05 trunk Linux

Comment 3

[Boris Zbarsky [:bzbarsky]]

Any chance of a minimal testcase?

Comment 4

[Mats Palmgren (inactive)]

Attachment: Testcase

Comment 5

[Mats Palmgren (inactive)]

Attachment: Testcase #2 (this works)

Comment 6

[Gyuris Gellért]

Attachment: testcase#A

Comment 7

[Gyuris Gellért]

Attachment: testcase#B

Comment 8

[Gyuris Gellért]

Attachment: testcase#C

The bug occurs not when an element is resized (see testcase#2, testcase#A and
tree a) below) but when the resizing of a parent is enforced by resizing it's
child (see testcase#1, testcase#B and tree b) below).

a. :: OK
BODY position: absolute -> resize
 |-DIV position: absolute, bottom: 0px
 
b. :: BUG
BODY position: absolute
 |-DIV position: static -> resize
 |-DIV position: absolute, bottom: 0px

The expected behaviour can be checked in Opera 7, I tested it under win2K,
Opera 7.03, 7.21 and 7.22. 

The case represented by the tree b) can be investigated when You resize the
child and after that resize the window too (see testcase#C), beacuse in the
case of resizing the window the child positioned to the bottom jumps down to
it's proper position at once. 

Are these cases good as minimal testcases?

Comment 9

[Boris Zbarsky [:bzbarsky]]

Yeah, they're fine.  The problem is made pretty clear by the last one of those
or the testcase in comment #4.

Comment 10

[Mats Palmgren (inactive)]

*** Bug 254813 has been marked as a duplicate of this bug. ***

Comment 11

[Boris Zbarsky [:bzbarsky]]

Fixed by checkin for bug 261064