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
diff --git a/diff.c b/diff.c
index ea7e597..3c6a3e0 100644
--- a/diff.c
+++ b/diff.c
@@ -3738,7 +3738,7 @@ static void prep_temp_blob(const char *path, struct diff_tempfile *temp,
 		blob = buf.buf;
 		size = buf.len;
 	}
-	if (write_in_full(temp->tempfile->fd, blob, size) != size ||
+	if (write_in_full(temp->tempfile->fd, blob, size) < 0 ||
 	    close_tempfile_gently(temp->tempfile))
 		die_errno("unable to write temp-file");
 	temp->name = get_tempfile_path(temp->tempfile);