Jasper aborted found by fuzzing

[stuartly]

Bug1:

stly@stly-XPS-8700:~/Desktop/TargetFuzz/Benchmark/VulBenchmark/jasper-2.0.14$ ./installed/bin/jasper -f fuzzing_output/crashes/id\:000000\,sig\:06\,src\:000000\,op\:havoc\,rep\:2 -F 1.jp2 -T jp2
jasper: /home/stly/Desktop/TargetFuzz/Benchmark/VulBenchmark/jasper-2.0.14/src/libjasper/jpc/jpc_math.c:113: int jpc_firstone(int): Assertion `x >= 0' failed.
Aborted

Bug2:

stly@stly-XPS-8700:~/Desktop/TargetFuzz/Benchmark/VulBenchmark/jasper-2.0.14$ ./installed/bin/jasper -f fuzzing_output/crashes/id\:000002\,sig\:06\,src\:000110\,op\:havoc\,rep\:2 -F 1.jp2 -T jp2
jasper: /home/stly/Desktop/TargetFuzz/Benchmark/VulBenchmark/jasper-2.0.14/src/libjasper/jpc/jpc_enc.c:186: uint_fast32_t jpc_abstorelstepsize(jpc_fix_t, int): Assertion `!((expn) & (~0x1f))' failed.
Aborted

Attachment is the POC.
POC.tar.gz

[MaxKellermann]

1. is CVE-2018-9055, see CVE-2018-9055 jasper-maint/jasper#9 and Reachable assertions in jpc_firstone #172, fixed by jasper-maint/jasper@e6c8d5a in our fork

2. is CVE-2018-9252, see CVE-2018-9252 jasper-maint/jasper#16 and A reachable assertion abort in function jpc_abstorelstepsize #173, fixed by jasper-maint/jasper@6cd1e1d in our fork

[jubalh]

Merged as

1. e6c8d5a
2. 6cd1e1d