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| author | Natanael Copa | 2016-08-03 16:21:52 +0200 |
|---|---|---|
| committer | Denys Vlasenko | 2016-08-15 01:26:28 +0200 |
| commit | 71cfbce655bcfa6d3e0154d441a33d3bfd1dca57 (patch) | |
| tree | 94ff19755254568b3f6dfc0fc6ed5131643b08fa | |
| parent | 7e6f9316a8bf3030da6c283e43aa0709d0cef259 (diff) | |
| download | busybox-71cfbce655bcfa6d3e0154d441a33d3bfd1dca57.zip busybox-71cfbce655bcfa6d3e0154d441a33d3bfd1dca57.tar.gz | |
gzip: fix compression level bug. Closes 9131
fix broken logic to get the gzip_level_config value from options -1 to
-9.
This fixes an off-by-one bug that caused gzip -9 output bigger files
than the other compression levels.
It fixes so that compression level 1 to 3 are actually mapped to level 4
as comments say.
It also fixes that levels -4 to -9 is mapped to correct level and avoids
out-of-bounds access.
Signed-off-by: Natanael Copa <ncopa@alpinelinux.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
| -rw-r--r-- | archival/gzip.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/archival/gzip.c b/archival/gzip.c index 8f1e4ff..9e0bee8 100644 --- a/archival/gzip.c +++ b/archival/gzip.c @@ -2220,10 +2220,7 @@ int gzip_main(int argc UNUSED_PARAM, char **argv) opt >>= ENABLE_GUNZIP ? 7 : 5; /* drop cfv[dt]qn bits */ if (opt == 0) opt = 1 << 6; /* default: 6 */ - /* Map 1..3 to 4 */ - if (opt & 0x7) - opt |= 1 << 4; - opt = ffs(opt >> 3); + opt = ffs(opt >> 4); /* Maps -1..-4 to [0], -5 to [1] ... -9 to [5] */ max_chain_length = 1 << gzip_level_config[opt].chain_shift; good_match = gzip_level_config[opt].good; max_lazy_match = gzip_level_config[opt].lazy2 * 2; |