452031 - SVG in XUL has incorrect height

Status: RESOLVED WONTFIX

(Core :: SVG, defect)

Description

[Justin Dolske [:Dolske]]

Attachment: Testcase

While working on bug 448909, I ran into problems with my SVG viewport not being sized as expected. I distilled it down to the following attachment.

Here, the window is split into half vertically and horizontally. The green box on the left should be the same height as the red box on the left. Instead, the red box is taller.

Replacing
  <svg:svg flex="1" style="background-color: red"/>
with
  <box flex="1" style="background-color: red"/>

works as expected.

Comment 1

[Neil Deakin]

(In reply to comment #0)
> Here, the window is split into half vertically and horizontally. The green box
> on the left should be the same height as the red box on the left. Instead, the
> red box is taller.

As you haven't specified a height for the SVG element, it defaults to some height, (100 pixels perhaps?). The default height of a box is 0. When the remaining empty space is divided between the svg/box and spacers, there is more empty space to divide between the box and spacer, so it appears smaller.
 

Comment 2

[Jonathan Watt [:jwatt]]

Ugh. SVG/XUL interaction is rather undefined, and whatever behavior you get is probably by accident.

Looking at the testcase, the extra height appears to come from the SVG's fallback height of 150px. If you set the 'height' attribute to that value you'll see you get the same rendering (and if you adjust it up and down you'll adjust the rendered height up and down). As a consequence, a hack would be to set height="0" to allow 'flex' to work without interference. You'll then get the rendering you want (for now).

Neil: the height defaults to 100%, which falls back to 150px when a percentage can't be resolved.

Comment 3

[Justin Dolske [:Dolske]]

I'd close this as invalid, but it's not clear from the last comment if this is really expected (if unfortunate) behavior or not.

No longer blocks 448909, in any case.

Comment 4

[Jonathan Watt [:jwatt]]

I don't think the current behavior makes any sense. Let's leave this open.

Comment 5

[Robert Longson [:longsonr]]

XUL is obsolete now.