RFR: 7131823: bug in GIFImageReader [v3]

[Dan Lutker]

> …xception: Index 4096 out of bounds for length 4096
> 
> Adapted from https://github.com/openjdk/jfx/commit/7b7050c46299c0e6771ae02fbb5ceaf22104d3e4
> 
> # Testing done
> Build locally on linux and ran jdk_imageio tests.

Dan Lutker has refreshed the contents of this pull request, and previous commits have been removed. The incremental views will show differences compared to the previous content of the PR. The pull request contains one new commit since the last revision:

  7131823: bug in GIFImageReader

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8371/files
  - new: https://git.openjdk.java.net/jdk/pull/8371/files/dac34ed4..beba00de

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8371&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8371&range=01-02

  Stats: 0 lines in 0 files changed: 0 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8371.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8371/head:pull/8371

PR: https://git.openjdk.java.net/jdk/pull/8371