Fix out of bounds read in isValidBoxFileType()

[piponazo]

Fix #2178

I just added a new unit test to validate the implementation and I also validated locally the changes with the POCs provided in the issue. Since in this case the buggy function was quite well isolated and I already had unit tests for it, I do not need it is needed to add some python tests taking as arguments the POC files. But let me know if you think otherwise.

[codecov]

Codecov Report

Merging #2180 (74622cf) into main (3b9fcb4) will not change coverage.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #2180   +/-   ##
=======================================
  Coverage   63.30%   63.30%           
=======================================
  Files          99       99           
  Lines       19596    19596           
  Branches     9559     9559           
=======================================
  Hits        12406    12406           
  Misses       5116     5116           
  Partials     2074     2074           

Impacted Files	Coverage Δ
src/jp2image_int.cpp	100.00% <100.00%> (ø)

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[kevinbackhouse]

Sometimes, I just add the poc images to test/data. Then they get picked up by the fuzzer automatically, which means that it takes less time for the fuzzer to find similar bugs in the future.

[kevinbackhouse]

I added one of the poc files to test/data.

[piponazo]

I added one of the poc files to test/data.

Ups, this change broke the execution of tests because now the regression_tests are automatically trying to run over all test data. I will take care of fixing the situation 😉

[kevinbackhouse]

I added one of the poc files to test/data.

Ups, this change broke the execution of tests because now the regression_tests are automatically trying to run over all test data. I will take care of fixing the situation wink

Sorry, I forgot about that. Thanks for fixing it!

[kmilos]

Fix on 0.27-maint as well please?

[piponazo]

Fix on 0.27-maint as well please?

Sure, thanks for the reminder. I thought about it yesterday but I forgot about it later 😅