code review 7938043: image/gif: tighten the checks for when the amount of an...

image/gif: tighten the checks for when the amount of an image's pixel
data does not agree with its bounds.

[nigeltao, 2013-03-21 05:03:56]

Hello r@golang.org (cc: golang-dev@googlegroups.com, jeff.allen@gmail.com),

I'd like you to review this change to
https://code.google.com/p/go/

[jeff.allen, 2013-03-21 08:00:02]

https://codereview.appspot.com/7938043/diff/5001/src/pkg/image/gif/reader.go
File src/pkg/image/gif/reader.go (right):

https://codereview.appspot.com/7938043/diff/5001/src/pkg/image/gif/reader.go#...
src/pkg/image/gif/reader.go:153: if err == io.EOF {
Why is it safe to continue here if err is something else? Then c will be in an
unknown state. (It seems like it's probably going to be 0, but it's not
guaranteed by the API.)

https://codereview.appspot.com/7938043/diff/5001/src/pkg/image/gif/reader.go#...
src/pkg/image/gif/reader.go:199: return errors.New("gif: too much image data")
make one copy of the error in global scope and return it in the three places.

[r, 2013-03-21 16:27:24]

LGTM

https://codereview.appspot.com/7938043/diff/5001/src/pkg/image/gif/reader.go
File src/pkg/image/gif/reader.go (right):

https://codereview.appspot.com/7938043/diff/5001/src/pkg/image/gif/reader.go#...
src/pkg/image/gif/reader.go:193: // Both lzwr and br should be exhausted:
reading from then
s/then/them/

https://codereview.appspot.com/7938043/diff/5001/src/pkg/image/gif/reader.go#...
src/pkg/image/gif/reader.go:199: return errors.New("gif: too much image data")
On 2013/03/21 08:00:02, jeff.allen wrote:
> make one copy of the error in global scope and return it in the three places.

do the "not enough" error too.

[nigeltao, 2013-03-22 03:42:16]

*** Submitted as https://code.google.com/p/go/source/detail?r=980d0c9ba7fd ***

image/gif: tighten the checks for when the amount of an image's pixel
data does not agree with its bounds.

R=r, jeff.allen
CC=golang-dev
https://codereview.appspot.com/7938043