Merge branch 'jk/write-in-full-fix'

Many codepaths did not diagnose write failures correctly when disks
go full, due to their misuse of write_in_full() helper function,
which have been corrected.

* jk/write-in-full-fix:
  read_pack_header: handle signed/unsigned comparison in read result
  config: flip return value of store_write_*()
  notes-merge: use ssize_t for write_in_full() return value
  pkt-line: check write_in_full() errors against "< 0"
  convert less-trivial versions of "write_in_full() != len"
  avoid "write_in_full(fd, buf, len) != len" pattern
  get-tar-commit-id: check write_in_full() return against 0
  config: avoid "write_in_full(fd, buf, len) < len" pattern

entry.c

@@ -257,7 +257,8 @@ static int write_entry(struct cache_entry *ce,
 	char *new;
 	struct strbuf buf = STRBUF_INIT;
 	unsigned long size;
-	size_t wrote, newsize = 0;
+	ssize_t wrote;
+	size_t newsize = 0;
 	struct stat st;
 	const struct submodule *sub;
 
@@ -332,7 +333,7 @@ static int write_entry(struct cache_entry *ce,
 			fstat_done = fstat_output(fd, state, &st);
 		close(fd);
 		free(new);
-		if (wrote != size)
+		if (wrote < 0)
 			return error("unable to write file %s", path);
 		break;
 	case S_IFGITLINK: