92272 - Possible malloc of 0 and traversal of unnecessary code

Status: VERIFIED FIXED

(Core :: DOM: Core & HTML, defect)

Description

[Mike Kaply [:mkaply]]

in nsGlobalWindow.cpp

http://lxr.mozilla.org/seamonkey/source/dom/src/base/nsGlobalWindow.cpp#2529

maxLength can come back 0 and then the Alloc is a 0 alloc and lots of 
unnecessary code is done.

Attaching diff to fix this

Comment 1

[Mike Kaply [:mkaply]]

Attachment: bail out if maxLength is zero

Comment 2

[Johnny Stenback (:jst)]

Thanks for the patch! We also need to do aResult.Truncate() if we return early
in this case.

Comment 3

[Mike Kaply [:mkaply]]

I assume you mean aReturn.Truncate().

Hmmm. Can we do this if GetMaxLength fails as well?

I was trying to avoid adding another if condition that checked for 
maxLength == 0 given that we want to do basically the same stuff for 
GetMaxLength failing or for maxLength == 0.

Comment 4

[Johnny Stenback (:jst)]

Yeah, that's what I meant :-)

You could even do that as the first thing in the method to cover all error
cases, zeroing out out parameters in error cases is arguably the right thing to
do, so no harm in doing that here. We don't need an extra if statement for this.

Comment 5

[Johnny Stenback (:jst)]

Fixed.

Comment 6

[Sivakiran Tummala]

verified the proposed fix is checked in...