===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/patch/patch.c,v
retrieving revision 1.70
retrieving revision 1.71
diff -u -r1.70 -r1.71
--- src/usr.bin/patch/patch.c	2022/08/03 07:25:44	1.70
+++ src/usr.bin/patch/patch.c	2022/08/03 07:30:37	1.71
@@ -1,4 +1,4 @@
-/*	$OpenBSD: patch.c,v 1.70 2022/08/03 07:25:44 op Exp $	*/
+/*	$OpenBSD: patch.c,v 1.71 2022/08/03 07:30:37 op Exp $	*/
 
 /*
  * patch - a program to apply diffs to original files
@@ -651,6 +651,8 @@
 		    || diff_type == UNI_DIFF)) {
 			say("Empty context always matches.\n");
 		}
+		if (first_guess == 0)
+			return 1;
 		return (first_guess);
 	}
 	if (max_neg_offset >= first_guess)	/* do not try lines < 0 */