After we write to the output file, the program exits. This naturally
closes the descriptor. But we should do an explicit close for two
reasons:
1. It's possible to hit an error on close(), which we should detect
and report via our exit code.
2. Leaking descriptors is a bad practice in general. Even if it isn't
meaningful here, it sets a bad example.
It is tempting to write:
if (write_in_full(fd, ...) < 0 || close(fd) < 0)
die_errno(...);
But that pattern contains a subtle problem that has resulted in
descriptor leaks before. If write_in_full() fails, we'll short-circuit
and never call close(), leaking the descriptor.
That's not a problem here, since our error path dies instead of
returning up the stack. But since we're trying to set a good example,
let's write it out as two separate conditions. As a bonus, that lets us
produce a slightly more specific error message.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
Another option is that the program should just write to stdout, then we
do not have to open or close it at all. ;)
t/helper/test-delta.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/t/helper/test-delta.c b/t/helper/test-delta.c
index 7945793078..52ea00c937 100644
--- a/t/helper/test-delta.c
+++ b/t/helper/test-delta.c
@@ -45,6 +45,8 @@ int cmd__delta(int argc, const char **argv)
fd = xopen(argv[4], O_WRONLY|O_CREAT|O_TRUNC, 0666);
if (write_in_full(fd, out_buf, out_size) < 0)
die_errno("write(%s)", argv[4]);
+ if (close(fd) < 0)
+ die_errno("close(%s)", argv[4]);
strbuf_release(&from);
strbuf_release(&data);
--
2.50.1.666.gdb1e186d6a
