- From: Gérard Talbot <css21testsuite@gtalbot.org>
- Date: Mon, 7 Nov 2011 11:13:13 -0800
- To: "Public CSS test suite mailing list" <public-css-testsuite@w3.org>
- Cc: "Arron Eicholz" <arron.eicholz@microsoft.com>
Hello, [nightly-unstable] http://test.csswg.org/suites/css2.1/nightly-unstable/html4/fixed-table-layout-001.htm [RC6] http://test.csswg.org/suites/css2.1/20110323/html4/fixed-table-layout-001.htm This testcase has a lot of difficulties. And I welcome any feedback from anyone wrt the issues involved in this testcase. 1- <meta name="assert" content="If a browser supports fixed table layout when 'width' is 'auto', a table will size to its containing block, minus any margin space (modified example from spec section 17.5.2.1)."> " The table's width may be specified explicitly with the 'width' property. A value of 'auto' (for both 'display: table' and 'display: inline-table') means use the automatic table layout algorithm. However, if the table is a block-level table ('display: table') in normal flow, a UA may (but does not have to) use the algorithm of 10.3.3 to compute a width and apply fixed table layout even if the specified width is 'auto'. If a UA supports fixed table layout when 'width' is 'auto', the following will create a table that is 4em narrower than its containing block: table { table-layout: fixed; margin-left: 2em; margin-right: 2em } " The spec says that if width is 'auto', then to use the automatic table layout algorithm and that a UA may still nevertheless resort to the algorithm of 10.3.3 and apply a fixed table layout. So, all this to say that if a testcase can be done, it should have a "may" flag. 2- The code in the testcase uses border-collapse: collapse; but there is no border anywhere applied at the table and in the table. Setting border-collapse: collapse; in the testcase is legal and okay but not logical and coherent. The only resulting layout effect in doing this is to zero the border-spacing of the table. So, setting border-spacing to 0 is much more compliant, coherent and understandable than setting border-collapse: collapse in the hope to achieve the same result. 3- font: 62.8% Ahem; The only achieved goal of setting such value is to counter-act the line-height: 1.2 of Firefox. 62.5% computes to 10px and with 62.8% the logic is to try to fill the gap above and below the Xes content... and it does not achieve this anyway. 4- The containing block div has a set width of 200px, the table has set horizontal margins of 50px and the table (which has one single row and one single cell) has 10 "X"es in Ahem font. All this adds up perfectly. So, as coded, the table can not render its content or be rendered in any other way different than the layout of optional statement in the spec. The testcase is "doctored" so that it can not fail to achieve the layout from the optional statement. The testcase does not reflect an implementation choice of logic (as given by the spec); the testcase is just too much constrained. So, if the testcase can not fail in achieving an intended layout, then it does not and can not really test what it was intended to test in the first place, to begin with. Generally speaking, a table with a single row that has a single cell with all kinds of ideal values and ideal constraints is not going to be very much convincing of anything or even useful or proving the implementation of an implementation. 5- Finally, I can not see a single browser implementing that optional recourse of the algorithm in section 10.3.3 and I've run a lot of test, including these tests: http://www.gtalbot.org/BrowserBugsSection/css21testsuite/fixed-table-layout-001x.html http://www.gtalbot.org/BrowserBugsSection/css21testsuite/fixed-table-layout-001y.html regards, Gérard -- Contributions to the CSS 2.1 test suite: http://www.gtalbot.org/BrowserBugsSection/css21testsuite/ CSS 2.1 Test suite RC6, March 23rd 2011: http://test.csswg.org/suites/css2.1/20110323/html4/toc.html CSS 2.1 test suite harness: http://test.csswg.org/harness/ Contributing to to CSS 2.1 test suite: http://www.gtalbot.org/BrowserBugsSection/css21testsuite/web-authors-contributions-css21-testsuite.html
Received on Monday, 7 November 2011 19:13:53 UTC