commit 68825776f4b4226dde4bbe13b07077e9448a9a3b
author Leon Scroggins III <scroggo@google.com> Fri Oct 26 14:15:02 2018 -0400
committer Skia Commit-Bot <skia-commit-bot@chromium.org> Mon Oct 29 12:18:52 2018 +0000
tree a9e590d484d8fa77cd21ee31eb92ea56b78d8a11
parent 1de48d8040aa263d4f79c023f9c31445310432a9

Ensure fSrcOffsetUnits is in a valid range

Bug: oss-fuzz:11114

fSrcOffsetUnits is where we start sampling from the image. It is
computed as

  (sampleX / 2) * fSrcBPP

(ignoring fSrcOffset, which is 0 for a GIF with a subset frame).
sampleX will be no wider than the full image, and we divide it by two to
sample points evenly spread through the image. But for a subset frame,
we need to use a different sampling rate to ensure that the sampled
points are within the width of the frame.

Change-Id: I4a313db096fbaea7d869927a9da5df9beb9f6706
Reviewed-on: https://skia-review.googlesource.com/c/165500
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Leon Scroggins <scroggo@google.com>