115477 - Images don't clip

Status: RESOLVED INVALID

(Core :: CSS Parsing and Computation, defect)

Description

[Bob Kanefsky]

Mozilla 0.9.6 (2001112011)

Image clipping doesn't seem to work for the simplest test case I can think of:

<img src="http://roving-mouse.com/logos/roving-mouse-bbg-188x200.jpg"
     style="clip: rect(50px, 100px, 100px, 50px)">

I will attach a screen shot.

Comment 1

[Bob Kanefsky]

Attachment: Screen shot of Mozilla and IE on same file

Comment 2

[Boris Zbarsky [:bzbarsky]]

Oh, boy... this is those clip errata from bug 87839 in action again...

The basic story (if I understand correctly) is that clip should either:

1) Be applied to elements that are block-level and absolutely positioned.  This
   is the "lost clip errata" version.
or
2) Be applied to all block or replaced elements, but only if overflow is not
   visible.  This is the "CSS2 spec as it stands" version.

In this case we have an <img> which is a replaced element, not a block.  It's 
not positioned.  Overflow is visible (default value).  So neither case #1 nor 
case #2 apply.  Looks like IE5/Mac implements a bastardization of the two 
cases...  <sigh>

We _really_ need this issue resolved by the working group.

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

I think according to the latest discussion in the WG (this was resolved at our
latest meeting) this is a bug in IE5 Mac...

Comment 4

[Bob Kanefsky]

Attachment: Three test cases

If I understand the preceding comments correctly, then all three test cases in
this attachment should cause clipping.	Only one of them does.

From the point of view of what I'm trying to implement, I'm happy to have found
one way to make it work in both IE and Mozilla (provided Windows IE behaves the
same way as Mac IE in this case).  From the point of view of correctness, it's
not clear whether Mozilla is following the standard, or even (given the
discussion in bug 87839 of the Lost Errata) what the standard is.  It would be
nice to have a clearly written interpretation of what the standard is, plus
some test cases showing how web page developers can use it.  Can someone
counter this attachment with a corrected version that will cause Mozilla to do
clipping as intended?

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

No, the 'lost errata' clip applies only to absolutely positioned elements.

Comment 6

[Boris Zbarsky [:bzbarsky]]

Perhaps my comment was unclear.  Mozilla (and Win IE6) implement the "lost 
errata" version of clip.  No browser implements the CSS2-compliant version, that 
I know.

David, should this just be invalid?  Is there a chance of official errata based 
on that last discussion?

Comment 7

[Ryan Hayle]

Since this hasn't been looked at in a while, I just thought I'd point out that
this hasn't been fixed as of 1.3b.  There seems no way to clip an image that is
relatively positioned.  This is mostly useful to me for removing cgi-generated
borders and such.

Also note this is not Mac-specific.  Please update!

Comment 8

[Boris Zbarsky [:bzbarsky]]

Ryan, you did read comment 4 and the bug referenced therein, right?  The WG has
not said anything useful since then.

Comment 9

[Simon Paquet [:sipaq]]

This bug is targeted at a Mac classic platform/OS, which is no longer supported
by mozilla.org. Please re-target it to another platform/OS if this bug applies
there as well or resolve this bug.

I will resolve this bug as WONTFIX in four weeks if no action has been taken.
To filter this and similar messages out, please filter for "mac_cla_reorg".

Comment 10

[Boris Zbarsky [:bzbarsky]]

This is an XP issue in any case.

Comment 11

[Hixie (not reading bugmail)]

In CSS2.1 it applies to absolutely positioned elements only. Since positioning 
an element makes it block-level, there is no inline ambiguity. HTH.

Comment 12

[Boris Zbarsky [:bzbarsky]]

OK.  Then this bug is invalid.