Closed Bug 716349 Opened 10 years ago Closed 9 years ago

ASSERTION: 'bad height: 'metrics.height>=0' and ASSERTION: bad width: 'metrics.width>=0' with mspace


(Core :: MathML, defect)

Not set





(Reporter: fredw, Assigned: fredw)




(3 files, 2 obsolete files)

mspace allows the user to give arbitrary dimensions and thus it is easy to produce assertions with negative values. For example:

<mspace width="-10px"/>
<mspace height="-10px"/>

We should fix nsMathMLmspaceFrame::Reflow. Note that mspace is cited among the MathML elements that permit "negative spacing" so we will have a bit more to do than just forbidding negative attribute values.
It will however maybe make sense to have the constraint "height >= 0 && width >= 0" rather than the less strict constraint "height + width >= 0". I hardly see how something like:

<mspace height="20px" depth="-10px"/> may be useful for a space.

In that case, the assertions for vertical metrics can be fixed by bug 411227, if we remove the nsMathMLElement::PARSE_ALLOW_NEGATIVE flag when parsing the values of the height/depth attributes.
Depends on: 411227
Attached patch crashtestSplinter Review
To apply after attachment 587416 [details] [diff] [review]...
Attached file testcase
As said in comment 1, I suggest to forbid negative values for height and depth of mspace.

For mspace with negative width, I think we should modify nsMathMLmspaceFrame::Reflow to set

mBoundingMetrics.width = NS_MAX(0, mWidth);
aDesiredSize.width = NS_MAX(0, mWidth);

and this should fix this bug.

Then, if we want to implement negative spaces, we should modify nsMathMLContainerFrame::RowChildFrameIterator to handle mX in a specific manner when mChildFrame->GetContent()->Tag() == == nsGkAtoms::mspace_ with mChildFrame->mWidth < 0. However, I'm not sure it will work when the mspace is a direct child of the <math/> element.
Assignee: nobody →
Attached patch Patch V1 (obsolete) — Splinter Review
Attachment #587736 - Flags: review?(karlt)
Attachment #587421 - Flags: review?(karlt)
Attachment #587421 - Flags: review?(karlt) → review+
Comment on attachment 587736 [details] [diff] [review]
Patch V1

Perhaps mention in one of the comments that nsLineLayout doesn't expect negative widths.
Attachment #587736 - Flags: review?(karlt) → review+
Blocks: 717546
No longer blocks: 717546
Depends on: 717546
Blocks: 717546
No longer depends on: 717546
Attached patch Patch V2 (obsolete) — Splinter Review
Attachment #587736 - Attachment is obsolete: true
Whiteboard: [good first bug]
Keywords: helpwanted
Attached patch Patch V3Splinter Review
Attachment #587991 - Attachment is obsolete: true
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