408772 - "ASSERTION: nscoord addition will reach or pass nscoord_MAX" on attachment 267831

Status: RESOLVED FIXED

(Core :: Layout, defect)

Description

[Daniel Holbert [:dholbert]]

Attachment: patch

Attachment 267831 [details] (from bug 383887) triggers:
###!!! ASSERTION: nscoord addition will reach or pass nscoord_MAX: '(PRInt64)a
+ (PRInt64)b < (PRInt64)nscoord_MAX', file ../../dist/include/gfx/nsCoord.h,
line 153

This was mentioned in
  https://bugzilla.mozilla.org/show_bug.cgi?id=383887#c12

I diagnosed this in
  https://bugzilla.mozilla.org/show_bug.cgi?id=383887#c17
and I'm attaching a patch.

Comment 1

[Daniel Holbert [:dholbert]]

Comment on attachment 293619 [details] [diff] [review]
patch

Summary of patch:
  Replace nscoord_MAX-unsafe arithmetic with safe call to NSCoordSaturatingSubtract.


Note: The third argument (nscoord_MAX) doesn't affect anything, because it only comes into play when we're doing nscoord_MAX - nscoord_MAX, and that shouldn't happen here because scrollbarWidth should never be that big.

Comment 2

[Boris Zbarsky [:bzbarsky]]

Comment on attachment 293619 [details] [diff] [review]
patch

r+sr=bzbarsky.  Sorry for this screwup; I haven't gotten used to the saturating stuff yet.  :(

Comment 3

[Daniel Holbert [:dholbert]]

patch checked in:

Checking in nsComboboxControlFrame.cpp;
/cvsroot/mozilla/layout/forms/nsComboboxControlFrame.cpp,v  <--  nsComboboxControlFrame.cpp
new revision: 1.425; previous revision: 1.42