From 8aeb526a2a9b732ebec0c36ea0056701c7d28348 Mon Sep 17 00:00:00 2001
From: Renaud Fivet <renaud.fivet@gmail.com>
Date: Tue, 27 Oct 2015 12:51:40 +0800
Subject: [PATCH] Clean up abs usage versus implementation. Clarify ernd()
 behaviour.

---
 estruct.h | 12 ------------
 eval.c    | 32 +++++++++++++-------------------
 eval.h    |  1 -
 3 files changed, 13 insertions(+), 32 deletions(-)

diff --git a/estruct.h b/estruct.h
index 35dba87..caa95d2 100644
--- a/estruct.h
+++ b/estruct.h
@@ -183,12 +183,6 @@
 #define       poke(a,b,c,d)   movedata(FP_SEG(c),FP_OFF(c),a,b,d)
 #endif
 
-#if	VMS
-#define	atoi	xatoi
-#define	abs	xabs
-#define	getname	xgetname
-#endif
-
 #if MSDOS & MSC
 #include	<dos.h>
 #include	<memory.h>
@@ -215,12 +209,6 @@
 #define	ENVFUNC	0
 #endif
 
-/*	Internal defined functions					*/
-
-#ifdef	abs
-#undef	abs
-#endif
-
 /* DIFCASE represents the integer difference between upper
    and lower case letters.  It is an xor-able value, which is
    fortunate, since the relative positions of upper to lower
diff --git a/eval.c b/eval.c
index ee77424..814a031 100644
--- a/eval.c
+++ b/eval.c
@@ -288,7 +288,7 @@ static int putctext( char *iline)
 static char *result ;		/* string result */
 static int ressize = 0 ;	/* mark result as uninitialized */
 
-static int ernd( void) ;
+static int ernd( int i) ;
 static int sindex( char *source, char *pattern) ;
 static char *xlat( char *source, char *lookup, char *trans) ;
 
@@ -537,13 +537,7 @@ static char *gtfun( char *fname) {
 		retstr = result ;
 		break ;
 	case UFRND | MONAMIC:
-		sz = atoi( arg1) ;
-		if( sz == 0)
-			sz = ernd() ;
-		else
-			sz = ernd() % abs( sz) + 1 ;
-
-		retstr = i_to_a( sz) ;
+		retstr = i_to_a( ernd( atoi( arg1))) ;
 		break ;
 	case UFABS | MONAMIC:
 		retstr = i_to_a( abs( atoi( arg1))) ;
@@ -1311,21 +1305,21 @@ char *mklower(char *str)
 	return str;
 }
 
-/*
- * take the absolute value of an integer
- */
-int abs(int x)
-{
-	return x < 0 ? -x : x;
-}
-
 /*
  * returns a random integer
+ *	ernd( 0) [ 0 .. 2147483647]
+ *  ernd( i) [ 1 .. abs( i)]
+ *		ernd( 1) [ 1]
+ *		ernd( -2147483648) [ 1 .. 2147483647] actually 2147482413
  */
-static int ernd( void) {
+static int ernd( int i) {
 	seed = seed * 1721 + 10007 ;
-	seed &= ~(1 << 31) ;	/* abs() introduces 176719 periodicity */
-	return seed ;
+	seed &= ~(1 << 31) ; /* avoid abs() which introduces 176719 periodicity */
+	if( i == 0)
+		return seed ;
+
+	i = i < 0 ? -i : i ;	/* abs( i) */
+	return seed % i + 1 ;
 }
 
 /*
diff --git a/eval.h b/eval.h
index e5943d5..701c2b8 100644
--- a/eval.h
+++ b/eval.h
@@ -22,7 +22,6 @@ int setvar( int f, int n) ;
 char *getval( char *token) ;
 int stol( char *val) ;
 char *mklower( char *str) ;
-int abs( int x) ;
 
 int clrmes( int f, int n) ;
 int writemsg( int f, int n) ;