9879 - HTML 4: <TD COLSPAN=0 ROWSPAN=0> doesn't work

Status: VERIFIED FIXED

(Core :: Layout: Tables, defect, P3)

Description

[Eric Pollmann]

From a posting to netscape.public.mozilla.layout:

From: [e-mail]
Tue 7/13 10:42AM
Subject: Gecko, ROW/COLSPAN=0, and appropriate error recovery?

I understand that Netscape's 5.0 browser will be using the Gecko engine
which reportedly supports all of HTML 4.0.

Can anyone test the Gecko engine for me with the following markup?

    <TABLE BORDER=1>
    <TR>
    <TD ROWSPAN=0>1</TD>
    <TD COLSPAN=0>2</TD>
    </TR><TR>
    <TD>5</TD>
    <TD>6</TD>
    </TR>
    </TABLE>

It should draw a table looking like:

    +-----------+
    | 1 | 2     |
    |   |-------|
    |   | 5 | 6 |
    +-----------+

since a ROWSPAN or COLSPAN of zero is defined to span all remaining rows
or columns of the table, respectively.  The current crop treat ROWSPAN and
COLSPAN as having a minimum value of 1, which creates:

    +-------+
    | 1 | 2 |
    |---+---|
    | 5 | 6 |
    +-------+

There's that, and also I need to know, if it supports these zero values
correctly, what error correction does it perform if you have a cell which
is to the right of a zero-spanned cell, such as:

    <TABLE BORDER=1>
    <TR>
    <TD COLSPAN=0>1</TD>
    <TD>3</TD>
    </TR>
    <TR>
    <TD>4</TD><TD>5</TD><TD>6</TD>
    </TR>
    </TABLE>

or, even worse, if you have two COLSPAN=0s in the same row, or if
ROWSPANned with COLSPAN=0 and a subsequent row has a cell that has to
occur in a spanned column:

    <TABLE BORDER=1>
    <TR>
    <TD>1</TD>
    <TD ROWSPAN=2 COLSPAN=0>2</TD>
    </TR>
    <TR>
    <TD>4</TD><TD>6</TD>
    </TR>
    </TABLE>

Otherwise, what would be the best way to handle such an error if
encountered?  Treat the zero-spanned cell like an overlapping on top of
the columns to the right similar to other multi-spanned cell errors?  I'm
working on a program which needs to address this problem if it is at all
to support zero input values for spannings, translating them to positive
values intelligently.

Thankfully there is no similar problem for ROWSPAN=0.

I've been looking through the whole HTML 4.0 specification and can't find
anything addressing this possibility, thus no recommendations for error
recovery.  I'll see about putting up a page on this tonight.

If this is the wrong netscape.public.mozilla.* group, please direct
followups to the right one, but keep comp.infosystems.www.authoring.html
in the crossposting.  I'm presuming the layout group deals with tables.
(Since I set Netscape to use MT-NewsWatcher for news:, I can't access
netscape.*, not even with snews:.)

Comment 1

[Eric Pollmann]

Attachment: Test case

Comment 2

[Eric Pollmann]

The exact wording in the spec (HTML4, 11.2.6) is:

rowspan = number [CN]
      This attribute specifies the number of rows spanned by the current cell.
      The default value of this attribute is one ("1"). The value zero ("0")
      means that the cell spans all rows from the current row to the last row of
      the table.

colspan = number [CN]
      This attribute specifies the number of columns spanned by the current
      cell. The default value of this attribute is one ("1"). The value zero
      ("0") means that the cell spans all columns from the current column to the
      last column of the table.

Comment 3

[Nicholas Cull]

Attachment: Error handling test case 1.

Comment 4

[Nicholas Cull]

Attachment: Error handling test case 2.

Comment 5

[Nicholas Cull]

Marking [TESTCASE].

Comment 6

[greg]

Attachment: Error handing test case 3

Comment 7

[karnaze (gone)]

*** Bug 11617 has been marked as a duplicate of this bug. ***

Comment 8

[leger]

Spoke to karnaze during bug triage today.  Moving to M11.  Not an M10 blocker.

Comment 9

[karnaze (gone)]

Moving to M13.

Comment 10

[karnaze (gone)]

Fixed with latest checkin.

Comment 11

[karnaze (gone)]

rowspan/colspan=0 now only works according to HTML 4 in strict mode. There are 
pages relying on the behavior where a value <= 0 becomes 1.

Comment 12

[Christine Hoffman]

Verified strict and transitional behavior across platform with 9/14 builds. 
Fixed in strict mode. Transitional works like Nav

Comment 13

[isourcein]

I am trying to resolve this bug on my page here: https://www.xerago.com/solutions
I set the default value of attribute as one ("1"). Still the problem exists.

Comment 14

[isourcein]

I am trying to resolve this bug on my page here: <a href="https://www.xerago.com/solutions">maximize customer value</a>
I set the default value of attribute as one ("1"). Still the problem exists.