[PATCH] create_delta_index: simplify condition always evaluating to true
From: Stefan Beller <hidden>
Date: 2016-06-15 22:58:25
Subsystem:
the rest · Maintainer:
Linus Torvalds
When checking the previous lines in that function, we can deduct that hsize must always be smaller than (1u<<31), since 506049c7df2c6 (fix >4GiB source delta assertion failure), because the entries is capped at an upper bound of 0xfffffffeU, so hsize contains a maximum value of 0x3fffffff, which is smaller than (1u<<31), so i will never be larger than 31. Signed-off-by: Stefan Beller <redacted> --- diff-delta.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/diff-delta.c b/diff-delta.c
index 93385e1..54da95b 100644
--- a/diff-delta.c
+++ b/diff-delta.c@@ -154,8 +154,15 @@ struct delta_index * create_delta_index(const void *buf, unsigned long bufsize) */ entries = 0xfffffffeU / RABIN_WINDOW; } + + /* + * Do not check i < 31 in the loop, because the assignement + * previous to the loop makes sure, hsize is definitely + * smaller than 1<<31, hence the loop will always stop + * before i exceeds 31 resulting in an infinite loop. + */ hsize = entries / 4; - for (i = 4; (1u << i) < hsize && i < 31; i++); + for (i = 4; (1u << i) < hsize; i++); hsize = 1 << i; hmask = hsize - 1;
--
1.8.4.rc3.498.g5af1768