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.

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.

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.

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

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

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)

Still need to run the regression tests on this.

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

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...

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...

ah, ok. Never mind, then.

Fixed.