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| author | cinap_lenrek <cinap_lenrek@felloff.net> | 2017-12-09 18:20:29 +0100 |
|---|---|---|
| committer | cinap_lenrek <cinap_lenrek@felloff.net> | 2017-12-09 18:20:29 +0100 |
| commit | a7ac020664f1de870b09807086565030246ad6fb (patch) | |
| tree | a2c6cc659514ea39f87c4937fae8f2035244f947 | |
| parent | 303fb4968634b7fd16815d4c16777dba0bf97f13 (diff) | |
| download | plan9front-a7ac020664f1de870b09807086565030246ad6fb.tar.xz | |
libflate: force non-empty huffman table in mkzprecode() for deflate
busybox gunzip fails on empty (offset) huffman tables,
so force one entry.
gzip states in a comment:
The pkzip format requires that at least one distance code exists,
and that at least one bit should be sent even if there is only one
possible code.
| -rw-r--r-- | sys/src/libflate/deflate.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/sys/src/libflate/deflate.c b/sys/src/libflate/deflate.c index 1eb7e866c..11c24cd6d 100644 --- a/sys/src/libflate/deflate.c +++ b/sys/src/libflate/deflate.c @@ -1063,6 +1063,11 @@ mkgzprecode(Huff *tab, ulong *count, int n, int maxbits) } if(bitcount[0] != 0) return 0; + if(nbits == 0){ + bitcount[1] = 1; + nbits = 1; + tab[0].bits = 1; + } return hufftabinit(tab, n, bitcount, nbits); } |