do not check odb_mkstemp return value for errors

The odb_mkstemp function does not return an error; it dies
on failure instead. But many of its callers compare the
resulting descriptor against -1 and die themselves.

Mostly this is just pointless, but it does raise a question
when looking at the callers: if they show the results of the
"template" buffer after a failure, what's in it? The answer
is: it doesn't matter, because it cannot happen.

So let's make that clear by removing the bogus error checks.
In bitmap_writer_finish(), we can drop the error-handling
code entirely. In the other two cases, it's shared with the
open() in another code path; we can just move the
error-check next to that open() call.

And while we're at it, let's flesh out the function's
docstring a bit to make the error behavior clear.

Signed-off-by: Jeff King <peff@peff.net>

1 files changed, 4 insertions, 3 deletions

diff --git a/builtin/index-pack.c b/builtin/index-pack.c
index 88d205f858..49e7175d9a 100644
--- a/builtin/index-pack.c
+++ b/builtin/index-pack.c
@@ -311,10 +311,11 @@ static const char *open_pack_file(const char *pack_name)
 			output_fd = odb_mkstemp(tmp_file, sizeof(tmp_file),
 						"pack/tmp_pack_XXXXXX");
 			pack_name = xstrdup(tmp_file);
-		} else
+		} else {
 			output_fd = open(pack_name, O_CREAT|O_EXCL|O_RDWR, 0600);
-		if (output_fd < 0)
-			die_errno(_("unable to create '%s'"), pack_name);
+			if (output_fd < 0)
+				die_errno(_("unable to create '%s'"), pack_name);
+		}
 		nothread_data.pack_fd = output_fd;
 	} else {
 		input_fd = open(pack_name, O_RDONLY);