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 <nc...@alpinelinux.org> --- See https://bugs.busybox.net/show_bug.cgi?id=9131 for more details archival/gzip.c | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/archival/gzip.c b/archival/gzip.c index 8f1e4ff..15ba57c 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..3 to 4 */ 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; -- 2.9.1 _______________________________________________ busybox mailing list busybox@busybox.net http://lists.busybox.net/mailman/listinfo/busybox
