1853043 - Table ends up taller in Firefox vs. other browsers, in quirks mode with percent-height scrollable child with tall content inside

Status: NEW

(Core :: Layout: Tables, defect)

Description

[Daniel Holbert [:dholbert]]

STR:

1. Load attached testcase

ACTUAL RESULTS:
Table is tall, i.e. ~600px tall (deriving its height from the tall content inside of the scrollable area)

EXPECTED RESULTS:
Table should be short. At least, it is in Chrome and Safari.

NOTES:
This specifically happens when we've got a percent height on the scrollable child, and this is related to the circular relationship between the height of the table and the percent height of the content inside its cell.

I imagine we're measuring the height of the table as if the percent were unresolvable, which then means that the percent-height descendant is as tall as its tall child, and so the table ends up with that same tall content-height (which we then finally do resolve the percent against, if we're in quirks mode as we are here). Whereas presumably Chrome/WebKit measure the height of the table as if the percent is resolvable, so the scrolled content never gets a chance to prop up the height of the table.

This is related to bug 1838524, but not quite the same. In this bug here, the testcase is quirks-mode, and we do eventually resolve the percent-height in the table; whereas that bug is standards-mode, and we don't resolve the percent-height in the table.

Comment 1

[Jonathan Kew [:jfkthame]]

Daniel, it looks like you forgot to attach your testcase here; do you still have it on hand, by any chance?

Comment 2

[Daniel Holbert [:dholbert]]

Attachment: testcase 1

Aww darn, it looks like I did.

Fortunately I was able to generate a testcase that I think matches what I described, though (based on my notes in comment 0, as modifications to a testcase from similar bug 1838524).

Firefox renders the table being tall here (based on the 600px content height on the innermost tall thing, plus scrollbar thickness and borders).
Chrome and Safari render the table as 100px tall here.

I think comment 0 goes into some theorizing as to why that might be the case.