216303 - [FIX]percentage heights don't work for auto-width floats

Status: RESOLVED FIXED

(Core :: Layout: Floats, defect, P1)

Description

[Timo K. Suoranta]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.4) Gecko/20030624

In the page at http://www.cs.helsinki.fi/u/tksuoran/div_height_percentage.html,
the three <div> elements should usually have the same size due to CSS height:
90% property. I believe that Mozilla does not support percentages in this case.
I tried to put the divs inside a div of different class which had fixed pixel
height but the problem remained.

Reproducible: Always

Steps to Reproduce:
1.Go to http://www.cs.helsinki.fi/u/tksuoran/div_height_percentage.html
2.
3.

Actual Results:  
The <div> elements appear as their height property would be auto.

Expected Results:  
The <div> elements should appear as their height property would 90%, which
usually makes the three elements the same height.

Comment 1

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

http://www.w3.org/TR/CSS21/visudet.html#the-height-property says:

<percentage>
    Specifies a percentage height. The percentage is calculated with respect to
the height of the generated box's containing block. If the height of the
containing block is not specified explicitly (i.e., it depends on content
height), and this element is not positioned, the value is interpreted like 'auto'.


Sometimes things like:

html, body { height: 100%; }

do what you want, although they may have other side-effects.

Comment 2

[Timo K. Suoranta]

Originally I did not have the html, body { height: 100%; } in my style. I had 
the bug before that and now that I removed it I still have the bug. Someone 
suggested it as a fix but it did not work. However at that time I forgot to 
remove it.

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

The problem is that percentage heights don't seem to be working for auto-width
floats.

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: testcase

Comment 5

[Carlos C.]

Attachment: another test case.

percentage unit (100%) inside a auto sized block renders wrong.

Comment 6

[Carlos C.]

Comment on attachment 144940 [details]
another test case.

my apologies, this test case seems to be bettter suited for Bug #208602.
(Browser:Layout:Block and Inline)

Comment 7

[Boris Zbarsky [:bzbarsky]]

Attachment: Patch.

Still need to run the regression tests on this.

Comment 8

[Boris Zbarsky [:bzbarsky]]

Attachment: Fix the assert

I ran this through the regression tests, and it passed...

Comment 9

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 170988 [details] [diff] [review]
Fix the assert

I'm hoping the logic you're moving doesn't actually do anything useful, but
r+sr=dbaron.

The assertion doesn't seem bulletproof, though, since widthUnit can be set to
auto if aContainingBlockWidth is NS_UNCONSTRAINEDSIZE.	You might want to see
if you can get the assertion to fire and maybe test to see if the behavior in
that case changes at all...

Comment 10

[Boris Zbarsky [:bzbarsky]]

widthUnit will be auto only if the actual unit is auto or if the actual unit is
percent and NS_UNCONSTRAINEDSIZE == aContainingBlockWidth, as you say.  But the
assert I added is in the else branch of:

if ((NS_UNCONSTRAINEDSIZE == aContainingBlockWidth) &&
    (eStyleUnit_Percent == mStylePosition->mWidth.GetUnit())) {
} else if (NS_STYLE_DISPLAY_TABLE == mStyleDisplay->mDisplay) {
} else {
}

(the first condition just didn't make the context, for which I apologize).  So
the assertion looks correct to me...

Comment 11

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

ah, ok.  Never mind, then.

Comment 12

[Boris Zbarsky [:bzbarsky]]

Fixed.