short i/o: fix calls to write to use xwrite or write_in_full

We have a number of badly checked write() calls.  Often we are
expecting write() to write exactly the size we requested or fail,
this fails to handle interrupts or short writes.  Switch to using
the new write_in_full().  Otherwise we at a minimum need to check
for EINTR and EAGAIN, where this is appropriate use xwrite().

Note, the changes to config handling are much larger and handled
in the next patch in the sequence.

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

1 files changed, 11 insertions, 22 deletions

diff --git a/ssh-fetch.c b/ssh-fetch.c
index 72965d6..4c172b6 100644
--- a/ssh-fetch.c
+++ b/ssh-fetch.c
@@ -20,22 +20,6 @@ static int fd_out;
 static unsigned char remote_version;
 static unsigned char local_version = 1;
 
-static ssize_t force_write(int fd, void *buffer, size_t length)
-{
-	ssize_t ret = 0;
-	while (ret < length) {
-		ssize_t size = write(fd, (char *) buffer + ret, length - ret);
-		if (size < 0) {
-			return size;
-		}
-		if (size == 0) {
-			return ret;
-		}
-		ret += size;
-	}
-	return ret;
-}
-
 static int prefetches;
 
 static struct object_list *in_transit;
@@ -53,8 +37,9 @@ void prefetch(unsigned char *sha1)
 	node->item = lookup_unknown_object(sha1);
 	*end_of_transit = node;
 	end_of_transit = &node->next;
-	force_write(fd_out, &type, 1);
-	force_write(fd_out, sha1, 20);
+	/* XXX: what if these writes fail? */
+	write_in_full(fd_out, &type, 1);
+	write_in_full(fd_out, sha1, 20);
 	prefetches++;
 }
 
@@ -97,8 +82,10 @@ int fetch(unsigned char *sha1)
 static int get_version(void)
 {
 	char type = 'v';
-	write(fd_out, &type, 1);
-	write(fd_out, &local_version, 1);
+	if (write_in_full(fd_out, &type, 1) != 1 ||
+	    write_in_full(fd_out, &local_version, 1)) {
+		return error("Couldn't request version from remote end");
+	}
 	if (xread(fd_in, &remote_version, 1) < 1) {
 		return error("Couldn't read version from remote end");
 	}
@@ -109,8 +96,10 @@ int fetch_ref(char *ref, unsigned char *sha1)
 {
 	signed char remote;
 	char type = 'r';
-	write(fd_out, &type, 1);
-	write(fd_out, ref, strlen(ref) + 1);
+	int length = strlen(ref) + 1;
+	if (write_in_full(fd_out, &type, 1) != 1 ||
+	    write_in_full(fd_out, ref, length) != length)
+		return -1;
 
 	if (read_in_full(fd_in, &remote, 1) != 1)
 		return -1;