commit 7a0ed0bb89ac7433010b23eeffb19353c9f7971d
author Aleks Totic <atotic@chromium.org> Wed May 05 03:28:26 2021
committer Blink WPT Bot <blink-w3c-test-autoroller@chromium.org> Wed May 05 03:43:30 2021
tree e11f6cd459ce990bedf6fcb3d29e308a1fdaffd3
parent babc2a1cf4a1d33aeaa6e14b4c615786f07a4805

[TablesNG] Width over percentage columns redistribution bugfix

Column width redistribution was incorrect if:
- table width was wider than max columns width
- all columns were percentage columns
- column min width was wider than intrinsic percent width

Something like this would trigger it:
  <td style="width:1%">  <- small percentage size
    <div style=width:500px> <- large min width

Its a bit more complicated than that because of reverse percentage
width computation, you have to hit just the right ration of min/%.

The correct fix matches FF/Legacy:
- distributed size is min-width + cell%/total% * excess width.

Bug: 1205135
Change-Id: I38187122e82ed7eeff2e4ec80ca45cfe8ef0e305
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2872538
Commit-Queue: Aleks Totic <atotic@chromium.org>
Reviewed-by: Ian Kilpatrick <ikilpatrick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#879205}

css/css-tables/tentative/colspan-redistribution.html

diff --git a/css/css-tables/tentative/colspan-redistribution.html b/css/css-tables/tentative/colspan-redistribution.html
index e440728..2797a1e 100644
--- a/css/css-tables/tentative/colspan-redistribution.html
+++ b/css/css-tables/tentative/colspan-redistribution.html
@@ -216,29 +216,31 @@
 </table>
 </div>
 
-<p 12 class="testdesc">Colspan&gt;1:Auto/400 C0:50%/150 C1:30%/150 C2:20/Auto
+<p 12 class="testdesc">Colspan&gt;1:Auto/468 C0:50%/150 C1:30%/150 C2:20/Auto
 This tests conflict resolution where min-width > redistributed min width.
-400-8px distributed max width tries to redistribute as 245|147, but gets constrained to 245|150 in Chrome.
-table width from C0 245/0.5 + 4*8 = 522
-table width from C1 150/0.3 + 4*8 = 532
-C0 = 50% of 500 = 250, C1 = 30% of 500 = 150 , C2 gets the remaining 100</p>
-<p class="error">Chrome/FF/Edge end up with tables of different widths: 532/590/685. Chrome's 2nd span cell seems 'most correct' at its original max width of 150. In FF, extra min-width seems to cause more width to be redistributed. If you hover over 30%/150 cell, its min width will change to 100px, and all browsers will agree.</p>
-<style>
-  .test12:hover {
-    width:100px !important;
-  }
-</style>
-<table data-expected-width="532">
+Colspanned redistribution: distributed 468-8 = 460 over C0/C1
+Colspanned 468px needs to distribute 460px over C0/C1.
+C0 percent size is 50% * 460 = 230
+C1 percent size is 30% * 460 = 138, defaults to min size of 150
+Column 1 size is 230 + 50%/80% * 80 = 280px
+Column 2 size is 150 + 30%/80% * 80 = 180px
+Column 3 remains 20px
+Assignable table inline size
+C1 dominates estimate: 180/30% + 4*8 = 632
+Compute final column widths from assignable table size:
+C0 = 50% of 600 = 300 C1 = 30% of 600 = 180 , C2 gets the remaining 120</p>
+<table data-expected-width="632">
   <tr>
-    <td style="width:50%" data-expected-width="250"><div style="width:150px">50%/150px</div></td>
-    <td style="width:30%" data-expected-width="150"><div class="test12" style="width:150px">30%/150px</div></td>
-    <td style="width:20px" data-expected-width="100">x</td>
+    <td style="width:50%" data-expected-width="300"><div style="width:150px">50%/150px</div></td>
+    <td style="width:30%" data-expected-width="180"><div style="width:150px">30%/150px</div></td>
+    <td style="width:20px" data-expected-width="120">x</td>
   </tr>
   <tr>
-    <td colspan=2 style=""><div style="width:400px">400px min</div></td>
+    <td colspan=2 style=""><div style="width:468px">408px min</div></td>
   </tr>
 </table>
 
+
 <p 13 class="testdesc"> Colspan&gt;1:Auto/400px C0:50%/75px/125px, C1:30%/75px/125px C2:20px/Auto
 Colspan&gt;1 cell distribution over different percentages.
 400-8px min width gets redistributed as 245/147 (no min width limits)