Use die_errno() instead of die() when checking syscalls

Lots of die() calls did not actually report the kind of error, which
can leave the user confused as to the real problem.  Use die_errno()
where we check a system/library call that sets errno on failure, or
one of the following that wrap such calls:

  Function              Passes on error from
  --------              --------------------
  odb_pack_keep         open
  read_ancestry         fopen
  read_in_full          xread
  strbuf_read           xread
  strbuf_read_file      open or strbuf_read_file
  strbuf_readlink       readlink
  write_in_full         xwrite

Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 4 insertions, 4 deletions

diff --git a/builtin-blame.c b/builtin-blame.c
index 7d8fbd5..fd6ca51 100644
--- a/builtin-blame.c
+++ b/builtin-blame.c
@@ -2008,23 +2008,23 @@ static struct commit *fake_working_tree_commit(const char *path, const char *con
 
 		if (contents_from) {
 			if (stat(contents_from, &st) < 0)
-				die("Cannot stat %s", contents_from);
+				die_errno("Cannot stat '%s'", contents_from);
 			read_from = contents_from;
 		}
 		else {
 			if (lstat(path, &st) < 0)
-				die("Cannot lstat %s", path);
+				die_errno("Cannot lstat '%s'", path);
 			read_from = path;
 		}
 		mode = canon_mode(st.st_mode);
 		switch (st.st_mode & S_IFMT) {
 		case S_IFREG:
 			if (strbuf_read_file(&buf, read_from, st.st_size) != st.st_size)
-				die("cannot open or read %s", read_from);
+				die_errno("cannot open or read '%s'", read_from);
 			break;
 		case S_IFLNK:
 			if (strbuf_readlink(&buf, read_from, st.st_size) < 0)
-				die("cannot readlink %s", read_from);
+				die_errno("cannot readlink '%s'", read_from);
 			break;
 		default:
 			die("unsupported file type %s", read_from);