473400 - CSS3 media queries not reapplied when using text-only zoom

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, defect, P3)

Description

[Stephan Grossklass]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.2; de-AT; rv:1.8.1.19) Gecko/20081204 SeaMonkey/1.1.14
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.2; de; rv:1.9.1b2) Gecko/20081201 Firefox/3.1b2

When using the old-style text-only zoom, FF 3.1b2 fails to reapply the media queries affecting "screen".

Upon changing the window size or when using the default "whole-page" zoom, however, it does work as expected.

On the example page given, the content max-width and line height are adjusted according to available width in 'em', and rendering of the ("pop-up") quick navigation menu on the left depends on available height, again in 'em'.

Thus it looks like text-only zoom does not update the effective dimensions of the visible area.

Even if this should not be a bug for whatever reason, it is unexpected behavior at the very least.

Reproducible: Always

Comment 1

[Nochum Sossonko [:Natch]]

I suspect that the text-only zoom is exactly as it sounds, text only. If the user wishes to zoom the content, that is what the regular zoom is for. Is this a regression and can you provide a testcase?

Comment 2

[philippe (part-time)]

Attachment: testcase

Even with text zoom, the background color should change between green and yellow - I think. It does with page zoom, but not with text zoom.

(tested with a window about 1100px wide)

Comment 3

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

This is clearly a valid bug, since the media queries are applied correctly after resizing the window one pixel.  The problem is that I didn't hook up text zoom changes to triggering media query recalculation.

Though I'd note that the only thing that's changing with text zoom is the meaning of the 'em' unit, not any effective dimensions.

Comment 4

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Attachment: patch

Simple patch; I had a little fun writing the test.

I want it separate from test_media_queries.html partly because it's Gecko-specific, but also because it doesn't have a whole lot in common.

I did confirm that two of the second block of tests (first run through 4...7, for text zoom) fail without the patch and the patch fixes them.

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Fixed: http://hg.mozilla.org/mozilla-central/rev/aa7c99bf9634

Comment 6

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

http://hg.mozilla.org/releases/mozilla-1.9.1/rev/8f2004bf8cf3