Bug 184308 – REGRESSION: Excessive table cell height when all rows have height set and rowspan > 1

• Component: Tables
• Status: NEW

[Tal Aloni]

Created attachment 337183 [details]
HTML Test Case

I have confirmed the presence of this bug in the latest Safari technology preview (11.1), as well as Safari 9 and 10 (and probably even earlier versions).
Attached a test case, the expected behavior is for the first table cell to have an height of 479px (as can be confirmed using Firefox & Chrome),
In Safari there is currently a very noticeable excessive height to the cell.

This bug may be related to bug 21397

[Radar WebKit Bug Importer]

<rdar://problem/39262534>

[Tal Aloni]

This bug is not present in Safari 6.0.5 / WebKit 536.30.1,
This bug is present in Safari 6.1.6 / WebKit 537.78.2

[Tal Aloni]

This problem is not present in Chrome 49.0.2623.112 / WebKit 537.36

[Ahmad Saleem]

I am able to reproduce this bug in Safari 15.6.1 and Safari Technology Preview 151 where the "No More Bugs!" table is shown in the center of visual viewport with empty void space on top and bottom, in case of other browsers (Chrome Canary 106 and Firefox Nightly 105), there is no void space on top and the "No More Bugs!" is on top rather than center of page. Just wanted to update latest testing results. Thanks!

[Karl Dubost]

In Firefox, Chrome 

                      HEIGHT
table ............... 479
 tbody .............. 479 
  tr ................  14   (style="height:14px;")
   td rowspan="32" .. 479   (style="height:479px;")
  tr ................  15   (style="height:15px;")
     (x 31)

31 x 15 = 465 -> + 14 = 479


In Safari

table ............... 944
 tbody .............. 944 
  tr ................ 479   (style="height:14px;")
   td rowspan="32" .. 944   (style="height:479px;")
  tr ................  15   (style="height:15px;")
     (x 31)

So we can see there is something very wrong about the computation.

31 x 15   = 465 
465 + 479 = 944 

It's like it is duplicating the size of something already computed.

[Karl Dubost]

Maybe something around here. 
https://github.com/WebKit/WebKit/blob/e60e4ad864876164321293a426e6cc34531881f9/Source/WebCore/layout/formattingContexts/table/TableLayout.cpp#L431-L443

[Tim Nguyen (:ntim)]

(In reply to Karl Dubost from comment #6)
> Maybe something around here. 
> https://github.com/WebKit/WebKit/blob/
> e60e4ad864876164321293a426e6cc34531881f9/Source/WebCore/layout/
> formattingContexts/table/TableLayout.cpp#L431-L443

That code is for the LFC prototype, not used in production.

You'd probably want to look into Source/WebCore/rendering

[Karl Dubost]

ha thanks. 
19 years old comment.  :) Things might have changed a bit. 
https://github.com/WebKit/WebKit/blame/4e87c5073b3ed5648e47a3ffe1f5128a5fdd81f8/Source/WebCore/rendering/RenderTableSection.cpp#L173-L179