unpack: replace xwrite() loop with write_in_full()

We have two packfile stream consumers, index-pack and
unpack-objects, that allow excess payload after the packfile stream
data. Their code to relay excess data hasn't changed significantly
since their original implementation that appeared in 67e5a5e
(git-unpack-objects: re-write to read from stdin, 2005-06-28) and
9bee247 (mimic unpack-objects when --stdin is used with index-pack,
2006-10-25).

These code blocks contain hand-rolled loops using xwrite(), written
before our write_in_full() helper existed. This helper now provides
the same functionality.

Replace these loops with write_in_full() for shorter, clearer
code. Update related variables accordingly.

Signed-off-by: Junio C Hamano <[email protected]>

Author: gitster

builtin/index-pack.c

@@ -1524,14 +1524,12 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 	struct strbuf pack_name = STRBUF_INIT;
 	struct strbuf index_name = STRBUF_INIT;
 	struct strbuf rev_index_name = STRBUF_INIT;
-	int err;
 
 	if (!from_stdin) {
 		close(input_fd);
 	} else {
 		fsync_component_or_die(FSYNC_COMPONENT_PACK, output_fd, curr_pack_name);
-		err = close(output_fd);
-		if (err)
+		if (close(output_fd))
 			die_errno(_("error while closing pack file"));
 	}
 
@@ -1566,17 +1564,8 @@ static void final(const char *final_pack_name, const char *curr_pack_name,
 		write_or_die(1, buf.buf, buf.len);
 		strbuf_release(&buf);
 
-		/*
-		 * Let's just mimic git-unpack-objects here and write
-		 * the last part of the input buffer to stdout.
-		 */
-		while (input_len) {
-			err = xwrite(1, input_buffer + input_offset, input_len);
-			if (err <= 0)
-				break;
-			input_len -= err;
-			input_offset += err;
-		}
+		/* Write the last part of the buffer to stdout */
+		write_in_full(1, input_buffer + input_offset, input_len);
 	}
 
 	strbuf_release(&rev_index_name);

builtin/unpack-objects.c

@@ -679,13 +679,7 @@ int cmd_unpack_objects(int argc, const char **argv, const char *prefix UNUSED)
 	use(the_hash_algo->rawsz);
 
 	/* Write the last part of the buffer to stdout */
-	while (len) {
-		int ret = xwrite(1, buffer + offset, len);
-		if (ret <= 0)
-			break;
-		len -= ret;
-		offset += ret;
-	}
+	write_in_full(1, buffer + offset, len);
 
 	/* All done */
 	return has_errors;