Re: [PATCH] remove unnecessary test and dead diagnostic

[Jeff King <peff@peff.net>]

On Thu, May 26, 2011 at 04:34:20PM +0200, Jim Meyering wrote:

> Argh.  I went in with blinders on, thinking that the caller was
> right in using a type of size_t, and then read this "xread" name and
> assumed that it would exit upon failure.

I've made the same mistake, as many of our x* functions are designed to
die on error.

> Subject: [PATCH] use the correct type (ssize_t, not size_t) for read-style function
> 
> * sha1_file.c (index_stream): Using an unsigned type,
> we would fail to detect a read error and then proceed to
> try to write (size_t)-1 bytes.

This version looks right to me.

There's another one, too:

-- >8 --
Subject: [PATCH] read_gitfile_gently: use ssize_t to hold read result

Otherwise, a negative error return becomes a very large read
value. We catch this in practice because we compare the
expected and actual numbers of bytes (and you are not likely
to be reading (size_t)-1 bytes), but this makes the
correctness a little more obvious.

Signed-off-by: Jeff King <peff@peff.net>
---
 setup.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/setup.c b/setup.c
index 013ad11..ce87900 100644
--- a/setup.c
+++ b/setup.c
@@ -382,7 +382,7 @@ const char *read_gitfile_gently(const char *path)
 	const char *slash;
 	struct stat st;
 	int fd;
-	size_t len;
+	ssize_t len;
 
 	if (stat(path, &st))
 		return NULL;
-- 
1.7.4.5.13.gd3ff5