diff -Naur a2tools/a2tools.c a2tools.patched/a2tools.c
--- a2tools/a2tools.c	2001-04-10 00:18:01.000000000 -0400
+++ a2tools.patched/a2tools.c	2023-05-31 23:25:37.538490402 -0400
@@ -541,7 +541,7 @@
 void a2out (void) {
     unsigned char listbuffer[256];
     unsigned int hop, next_trk, next_sec, i, j;
-    void (*postproc_function)(void);
+    void (*postproc_function)(void) = NULL;
     if (!dir_do(dir_find_name)) quit(6,"File not found.\n");
     hop = begun = 0;
     next_trk=dir_entry_data[0];
@@ -817,7 +817,7 @@
 
     /* prepare source filename by padding blanks */
     i=0;
-    while(i<30 && a2_name[i]) padded_name[i]=a2_name[i++] & 0x7f;
+    while(i<30 && a2_name[i]) { padded_name[i]=a2_name[i] & 0x7f; i++; }
     while(i<30) padded_name[i++]=' ';
 
     /* get VTOC and check validity */