# [PATCH] Fix a comparison bug in diff-delta.c 3 messages from 2006-08-23 to 2006-08-23. Participants: Pierre Habouzit, Johannes Schindelin. Thread: https://gitlist.dev/t/5362 ## Pierre Habouzit, 2006-08-23 09:17 Subject: [PATCH] Fix a comparison bug in diff-delta.c Message-ID: <1156324675415-git-send-email-madcoder@debian.org> URL: https://gitlist.dev/e/1156324675415-git-send-email-madcoder%40debian.org ``` (1 << i) < hspace is compared in the `int` space rather that in the unsigned one. the result will be wrong if hspace is between 0x40000000 and 0x80000000. Signed-off-by: Pierre Habouzit --- This is a replacement for <1156300368160-git-send-email-madcoder@debian.org> avoiding the ugly cast, and using 1u instead. diff-delta.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/diff-delta.c b/diff-delta.c index 7da9205..51e2e56 100644 --- a/diff-delta.c +++ b/diff-delta.c @@ -152,7 +152,7 @@ struct delta_index * create_delta_index( initialization in create_delta(). */ entries = (bufsize - 1) / RABIN_WINDOW; hsize = entries / 4; - for (i = 4; (1 << i) < hsize && i < 31; i++); + for (i = 4; (1u << i) < hsize && i < 31; i++); hsize = 1 << i; hmask = hsize - 1; -- 1.4.1.1 ``` ## Johannes Schindelin, 2006-08-23 13:45 Subject: Re: [PATCH] Fix a comparison bug in diff-delta.c Message-ID: URL: https://gitlist.dev/e/Pine.LNX.4.63.0608231542380.28360%40wbgn013.biozentrum.uni-wuerzburg.de In-Reply-To: <1156324675415-git-send-email-madcoder@debian.org> ``` Hi, On Wed, 23 Aug 2006, Pierre Habouzit wrote: > - for (i = 4; (1 << i) < hsize && i < 31; i++); > + for (i = 4; (1u << i) < hsize && i < 31; i++); The variable i never takes on the value 31 (or any higher value), so there is no bug here. Unless you port git to a system where an int has less than 32 bit. Ciao, Dscho ``` ## Pierre Habouzit, 2006-08-23 14:31 Subject: Re: [PATCH] Fix a comparison bug in diff-delta.c Message-ID: <200608231631.12958.madcoder@debian.org> URL: https://gitlist.dev/e/200608231631.12958.madcoder%40debian.org In-Reply-To: ``` Le mer 23 août 2006 15:45, Johannes Schindelin a écrit : > Hi, > > On Wed, 23 Aug 2006, Pierre Habouzit wrote: > > - for (i = 4; (1 << i) < hsize && i < 31; i++); > > + for (i = 4; (1u << i) < hsize && i < 31; i++); > > The variable i never takes on the value 31 (or any higher value), so > there is no bug here. Unless you port git to a system where an int > has less than 32 bit. that remains quite tasteless though, and maybe that patch can be integrated to the "cleanup" series I sent later today. -- ·O· Pierre Habouzit ··O madcoder@debian.org OOO http://www.madism.org ```