Introduce usagef() that takes a printf-style format

diff --git a/combine-diff.c b/combine-diff.c
index 1a6f9d1df5b7dcafbdaa2d64c45554e129972be2..5b63af1eeb71907f23117bc552fa7a4019f09722 100644 (file)
--- a/combine-diff.c
+++ b/combine-diff.c
@@ -745,7 +745,7 @@ static void show_patch_diff(struct combine_diff_path *elem, int num_parent,
 
                        done = read_in_full(fd, result, len);
                        if (done < 0)
-                               die("read error '%s'", elem->path);
+                               die_errno("read error '%s'", elem->path);
                        else if (done < len)
                                die("early EOF '%s'", elem->path);