Clean up write_in_full() users

With the new-and-improved write_in_full() semantics, where a partial write
simply always returns a real error (and always sets 'errno' when that
happens, including for the disk full case), a lot of the callers of
write_in_full() were just unnecessarily complex.

In particular, there's no reason to ever check for a zero length or
return: if the length was zero, we'll return zero, otherwise, if a disk
full resulted in the actual write() system call returning zero the
write_in_full() logic would have correctly turned that into a negative
return value, with 'errno' set to ENOSPC.

I really wish every "write_in_full()" user would just check against "<0"
now, but this fixes the nasty and stupid ones.

Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Signed-off-by: Junio C Hamano <junkio@cox.net>

sha1_file.c

@@ -1618,14 +1618,7 @@ int move_temp_to_file(const char *tmpfile, const char *filename)
 
 static int write_buffer(int fd, const void *buf, size_t len)
 {
-	ssize_t size;
-
-	if (!len)
-		return 0;
-	size = write_in_full(fd, buf, len);
-	if (!size)
-		return error("file write: disk full");
-	if (size < 0)
+	if (write_in_full(fd, buf, len) < 0)
 		return error("file write error (%s)", strerror(errno));
 	return 0;
 }

write_or_die.c

@@ -58,14 +58,7 @@ int write_in_full(int fd, const void *buf, size_t count)
 
 void write_or_die(int fd, const void *buf, size_t count)
 {
-	ssize_t written;
-
-	if (!count)
-		return;
-	written = write_in_full(fd, buf, count);
-	if (written == 0)
-		die("disk full?");
-	else if (written < 0) {
+	if (write_in_full(fd, buf, count) < 0) {
 		if (errno == EPIPE)
 			exit(0);
 		die("write error (%s)", strerror(errno));
@@ -74,16 +67,7 @@ void write_or_die(int fd, const void *buf, size_t count)
 
 int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
 {
-	ssize_t written;
-
-	if (!count)
-		return 1;
-	written = write_in_full(fd, buf, count);
-	if (written == 0) {
-		fprintf(stderr, "%s: disk full?\n", msg);
-		return 0;
-	}
-	else if (written < 0) {
+	if (write_in_full(fd, buf, count) < 0) {
 		if (errno == EPIPE)
 			exit(0);
 		fprintf(stderr, "%s: write error (%s)\n",
@@ -96,16 +80,7 @@ int write_or_whine_pipe(int fd, const void *buf, size_t count, const char *msg)
 
 int write_or_whine(int fd, const void *buf, size_t count, const char *msg)
 {
-	ssize_t written;
-
-	if (!count)
-		return 1;
-	written = write_in_full(fd, buf, count);
-	if (written == 0) {
-		fprintf(stderr, "%s: disk full?\n", msg);
-		return 0;
-	}
-	else if (written < 0) {
+	if (write_in_full(fd, buf, count) < 0) {
 		fprintf(stderr, "%s: write error (%s)\n",
 			msg, strerror(errno));
 		return 0;