471728 - reftest fails while displaying xml and the math elements

Status: RESOLVED WORKSFORME

(Core :: MathML, defect)

Description

[Joel Maher ( :jmaher ) (UTC -8)]

Attachment: sample test file

One of the reftests /layout/reftests/bugs/355548-3.xml fails.  After further investigation it appears that the failed portion is in reference to how mathbackground is used.  In the test which uses mathbackground, the whole background is green, even inbetween the different style elements (which is correct).  In the reference image, there is no mathbackground, just a background attribute set and this displays a green background like the test, but in between the different elements, there is a space.

In looking at this on firefox and fennec desktop (to see what is expected), the reference image is displayed incorrectly.  I have attached xmlcolor.xml to show an example of this.

Comment 1

[Joel Maher ( :jmaher ) (UTC -8)]

moving to test case component

Comment 2

[Karl Tomlinson (:karlt)]

It is not necessarily wrong to have white between the backgrounds of the elements, but I think it is wrong for the test and reference to be rendering differently.

The area for the background comes from the character cells of the text content.
I suspect that the fonts or font-rendering options on this system are such that the inked area of the glyphs is slightly beyond the character cells.  This "overflow" is considered in the spacing between the <mi> elements, and so white is visible between the elements.

The <mstyle> elements are implemented with an <mrow>.  That <mrow> is incorrectly changing the rendering of its child content by changing the background area (frame rect) to include the glyph overflow.  The test uses <mstyle> elements and so there is more green.

Comment 3

[Joel Maher ( :jmaher ) (UTC -8)]

this test is passing on beta3 build of fennec on maemo.