1691374 - Image inside "preserve aspect ratio" solution invisible (back-computed percent height)

Status: NEW

(Core :: Layout, defect, P3)

Description

[Dennis Schubert [:denschub]]

Attachment: testcase.html

STR:

1. Open the attached test case.

Expected:

• Picture of a mask with the grumpy cat printed on it is visible.

Actual:

• Nothing is visible.

---

This works in Chromium. I don't exactly know what's going on here, so I'll file this in Core::Layout.

Comment 1

[Emilio Cobos Álvarez (:emilio)]

So, if the padding was fixed rather than a percentage, this would clearly be a bug, because we should be able to figure out the percentage to give the image an intrinsic size.

However, with the padding being a percentage, we don't really know what that percentage resolves against at that point, so it's unclear to me what Blink/WebKit is doing...

Comment 2

[Emilio Cobos Álvarez (:emilio)]

So percentage padding is always a percentage of the containing block... It seems Blink / WebKit is also back-computing inline sizes, for blocks at least, which seems kinda wild to me...

Comment 3

[Dennis Schubert [:denschub]]

Emilio, the site and the testcase are still broken, but the blocker bug is closed. Is there another bug that tracks the core difference here, or is this it?

Comment 4

[Emilio Cobos Álvarez (:emilio)]

I think this is pretty much it. This has to do

Comment 5

[Emilio Cobos Álvarez (:emilio)]

Sorry that was meant to do "This has to do with how we back-compute percentage heights for some intrinsic sizing operations, which is not a very well defined mechanism"