114867 - layout issue with display:block applied to a table

Status: RESOLVED INVALID

(Core :: Layout, defect)

Description

[Emmanuel Bourg]

If the style "display:block" is applied to a table, its layout is changed. Since
'block' is the default value for the 'display' style attribute on a table
element, this action should have no visible effect.

Comment 1

[Emmanuel Bourg]

Attachment: example of display:block applied to a table

Comment 2

[Richard Brodie]

The default value of the display property for TABLE is likely to be 'table'. 

Comment 3

[Boris Zbarsky [:bzbarsky]]

Per CSS2 the default display of table elements is "table" (yes, IE gets this
wrong).

Comment 4

[Emmanuel Bourg]

I wasn't aware of this rule of CSS2, thank you. However this doesn't explain why
a table layout is broken when display:block is applied. The CSS2 spec states :

http://www.w3.org/TR/CSS2/tables.html#q2

<i>The default style sheet for HTML 4.0 in the appendix illustrates the use of
these values for HTML 4.0:

TABLE    { display: table }
TR       { display: table-row }
THEAD    { display: table-header-group }
TBODY    { display: table-row-group }
TFOOT    { display: table-footer-group }
COL      { display: table-column }
COLGROUP { display: table-column-group }
TD, TH   { display: table-cell }
CAPTION  { display: table-caption }

User agents may ignore these 'display' property values for HTML documents, since
authors should not alter an element's expected behavior.
</i>

Since altering the display property value to 'block' seems to break the table
layout, Mozilla should follow the recommendation and actually ignore attempts to
set it to anything else but 'table' (and maybe 'none' of course).

Comment 5

[Boris Zbarsky [:bzbarsky]]

That's not a _recommendation_.  A recommendation would say "should".  This says
"may".  So it's a violation of the spec which is allowable in some circumstances
for some reason.

QA to hixie, who has the final word on this sort of thing.

Comment 6

[Emmanuel Bourg]

Replace "recommendation" by "suggestion" in my previous comment if you want :)
Mozilla _may_ ignore the value, and i'm giving - i think - a good reason for it
to do so (a layout change).

Comment 7

[Boris Zbarsky [:bzbarsky]]

No, a good reason could be "This is commonly misused on very popular sites", or
"We have a layout engine that has no concept of display:table"....  In my
opinion, of course.

Comment 8

[Christopher Aillon (sabbatical, not receiving bugmail)]

"may" != "must"

This bug as it stands is invalid.  We are not required by the spec to ignore
this and it is obvious that we don't.  We properly apply the display as
specified in the CSS and are required to since we do not ignore this display
property.

However, if you feel that we should ignore the display property in this
instance, it is a different issue and thus a different bug.  Please search
Bugzilla to avoid dupes.