246706 - inconsistency in dealing with inflexible spacers

Status: RESOLVED FIXED

(Core :: XUL, defect)

Description

[Brian Ryner (not reading)]

If you have a spacer that has only a min-width specified in CSS, and is not
flexible, then the parent box will miscalculate how much space is needed.  This
results in a shortage of space when the parent box lays out its children so that
the last child may not get its min-width even if there is plenty of room.

Here's what causes the problem:
- In nsSprocketLayout::GetMinWidth(), we use the preferred size as the min size
for inflexible children.  This is the size used when computing the min-width of
the parent box.  Since the preferred width is not specified, it uses 0 as the
min width.
- In nsSprocketLayout::ComputeChildSizes() (used to lay out the children), we do
the same thing, but these sizes have previously been bounds-checked in
PopulateBoxSizes to ensure that min <= pref <= max.  So the min-size used here
is the actual min size from CSS.  This inconsistency is the source of the problem.

Since most of the box code assumes that min <= pref <= max, I think this should
be the case for nsBox::GetPrefSize() as well.  It's already done in
nsContainerBox::GetPrefSize, which is why this bug only affects leaf boxes such
as spacers.

Comment 1

[Brian Ryner (not reading)]

Attachment: testcase

The label should not wrap.  Instead, the parent box should expand to give it
enough space.

Comment 2

[Brian Ryner (not reading)]

Attachment: patch

Comment 3

[Brian Ryner (not reading)]

checked in

Comment 4

[Brian Ryner (not reading)]

checked in on aviary branch.

Comment 5

[Brian Ryner (not reading)]

Comment on attachment 150745 [details] [diff] [review]
patch

We should take this for 1.7 since we're taking the gtk2 native theme changes, I
think this is needed for that to work properly.

Comment 6

[Mike Kaply [:mkaply] (PTO until Sept 14)]

Comment on attachment 150745 [details] [diff] [review]
patch

a=mkaply for 1.7 - please mark fixed1.7.x when checked in.