--- cvsnt-2.5.05.3744/diff/diff3.c~	2021-10-23 22:29:35.000000000 +0200
+++ cvsnt-2.5.05.3744/diff/diff3.c	2021-10-23 22:32:54.900316124 +0200
@@ -205,8 +205,8 @@
 static int merge;
 
 /* I/O mode: nonzero only if using binary input/output.  */
-int binary_input;
-int binary_output;
+extern int binary_input;
+extern int binary_output;
 
 diff_encoding_type encoding3 = {0};
 int no_unlink;