The default value for border-collapse is separate. If you add the attribute rules="all", then the value of border-collapse becomes collapse; a given value to cellspacing is ignored. Opera 6 (O6 does not support the rules attribute anyway) and MSIE 6 do not react this way.

Agreed, that seems bad for rules="all" mapping. I'll try to remember to get to this when I work on the other bug I own about cleaning up the code so it doesn't use PostResolveCallbacks.

This is being caused by the rule: table[rules] { border-collapse: collapse; } in html.css

> This is being caused by the rule... in html.css. So then, this could be fixed by adding table[rules="all"] { border-collapse: separate; }

Or changing the selector to table[rules]:not([rules="all"])

FWIW, bug 21076 was reopened for what I think was essentially this issue.

I don't even understand why one would want to declare a css rule where the [rules] selector determines somehow the border-collapse property value of a table. That, I don't understand. MSIE 6 does not work like that.

Borders on rows and columns have no effect in the separated borders model. That's why we need to use the collapsed borders model for tables with 'rules'. http://www.w3.org/TR/REC-CSS2/tables.html#separated-borders What MSIE is doing here is, I think, not actually possible in CSS. (And you can't do it with CSS in MSIE, either.) In a table with rules=cols, the vertical borders are painted *into* the cellspacing to connect them from cell to cell.

Re comment #8 So, this quote [ from http://www.w3.org/TR/REC-CSS2/tables.html#separated-borders ] should be decisive: "In this (separated border) model, each cell has an individual border. (...) Rows, columns, row groups, and column groups cannot have borders (i.e., user agents must ignore the border properties for those elements)." So in other words: 1) table[rules="all"] implies border-collapse:separate 2) table[rules="cols"] implies border-collapse:collapse 3) table[rules="rows"] implies border-collapse:collapse 4) table[rules="groups"] implies border-collapse:collapse 5) table[rules="none"] implies border-collapse:collapse (?!?) Did I get this right? So, this bug could be solved by modifying html.css with these css3 attribute selectors: table[rules*="o"] {border-collapse:collapse;} /* every rules that has a value with the substring "o" at least once */ or table[rules]:not([rules="all"]) {border-collapse:collapse;} /* all of the rules values except when rules="all" */ and table[rules="all"] {border-collapse:separate;}

table[rules]:not([rules="all"]) {border-collapse:collapse;} ...would also match table with no rules attribute. Better would be to list the values intended to affect border-collapse. Anyway, this can't be done in html.css since it needs to be considered as author level style (it's a presentational attribute) so it must be done at the attribute mapping level.

I'm against the idea that any of the values for the HTML attribute 'rules' should imply 'border-collapse:collapse'. If the author hasn't explicitly specified 'collapse' it should be 'separate', after all what would you do when the author explicitly have style="border-collapse:separate" and rules="all" ? I think the IE6 implementation of "separate rules" is excellent and in spirit with the HTML spec regarding 'rules' (see attachment 101843 [details].) IMHO, that is the rendering we should implement too.

Mats, what do you make of this which can be read at section 17.6.1 of CSS2 and CSS2.1: "In this (separated border) model, each cell has an individual border. (...) Rows, columns, row groups, and column groups cannot have borders (i.e., user agents must ignore the border properties for those elements)." Toward the end of section 17.6.2 of CSS2 and CSS2.1, the W3C give an example of a table with rules="rows"; the border-collapse:collapse declaration is explicitly stated to achieve that. {The top border of the table is set to 'hidden' to suppress the top border of the first row. This implements the "rules" attribute of HTML 4.0 (rules="rows"). TABLE[rules=rows] TR { border-top: solid } TABLE[rules=rows] { border-collapse: collapse; border-top: hidden } }

*** Bug 187258 has been marked as a duplicate of this bug. ***

*** Bug 188883 has been marked as a duplicate of this bug. ***

*** Bug 199573 has been marked as a duplicate of this bug. ***

Comment on attachment 139525 [details] [diff] [review] patch sr=bzbarsky

Borders still have broken styles for cols, rows and groups. Why? I have a table with <colgroup span=2>, <td colspan=2> and <td rowspan=2> and simply want to have it looking the same way as simple tables. Without any CSS hacks if possible. On IE it works as expected (http://bugzilla.mozilla.org/attachment.cgi?id=101843&action=view)

Comment on attachment 139525 [details] [diff] [review] patch this will probably still match rules="", but it fixes this bug, which is for me more a reaction to public pressure than content driven.

Why was this never checked in?

This was assigned and a patch was made. Why wasn't it checked in? Status update anyone? Ian, David?

Comment on attachment 139525 [details] [diff] [review] patch a=asa

Fix checked in to trunk, 2005-04-28 13:47 -0700.

The rules="all" part of this got backed out because it caused bug 310100. It looks like we need to get bug 43178 fixed...

bug 43178 got fixed the test case is http://mxr.mozilla.org/mozilla-central/source/layout/reftests/table-bordercollapse/borderhandling-rules-border.html