1d02fe3264e9f1d78757a31540e33c17d05691d8
galt
  Sat Jan 4 22:56:49 2025 -0800
added an explanatory note about using 0 not NULL to ArraySize macro.

diff --git src/inc/common.h src/inc/common.h
index 09764f2..48f7a85 100644
--- src/inc/common.h
+++ src/inc/common.h
@@ -189,31 +189,32 @@
 /*
 _IF(0)(it was not 0, it was 0)
  Should be "it was 0" 
 
 _IF(1)(it was 1, it was not 1)
  Should be "it was 1" 
 
 _IF(123)(it was 123)(it was not 123)
  Should be "it was 123" 
 
 // Could not get NULL to work as it gets replaced by ((void *)0) and then ## makes a invalid token created error.
 _IF(NULL)(it was not null,it was null)
  Should be "it was null" but does not work
 */
 
-/* How big is this array? */
+/* How big is this array? 
+ *  Parameter a must not be NULL. Use 0 instead, or just the array name. */
 #define ArraySize(a) (_IF(a)((sizeof(a) / sizeof((a)[0])),(size_t)0))
 
 #define uglyf printf  /* debugging printf */
 #define uglyAbort errAbort /* debugging error abort. */
 #define uglyOut stdout /* debugging fprintf target. */
 
 size_t memCheckPoint();
 /* Return the amount of memory allocated since last called. */
 
 void *needMem(size_t size);
 /* Need mem calls abort if the memory allocation fails. The memory
  * is initialized to zero. */
 
 void *needLargeMem(size_t size);
 /* This calls abort if the memory allocation fails. The memory is