From 01829a42033ded445d16ece65190d75bd513b361 Mon Sep 17 00:00:00 2001
From: ceriel <none@none>
Date: Wed, 31 Jan 1990 11:01:53 +0000
Subject: [PATCH] Fixes: random did not work properly, and RealToString did not
 deal with numbers not fitting in the format given properly

---
 lang/m2/libm2/RealConver.mod | 13 +++++++++++--
 lang/m2/libm2/random.mod     | 33 ++++++++++++++++++++++-----------
 2 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/lang/m2/libm2/RealConver.mod b/lang/m2/libm2/RealConver.mod
index 2e29b9765..493dc914b 100644
--- a/lang/m2/libm2/RealConver.mod
+++ b/lang/m2/libm2/RealConver.mod
@@ -85,8 +85,8 @@ IMPLEMENTATION MODULE RealConversions;
 	ind2 := ndigits+1;
 
 	IF NOT ecvtflag THEN 
-		IF INTEGER(ind2) + pointpos < 0 THEN
-			ind2 := 0;
+		IF INTEGER(ind2) + pointpos <= 0 THEN
+			ind2 := 1;
 		ELSE
 			ind2 := INTEGER(ind2) + pointpos
 		END;
@@ -119,6 +119,10 @@ IMPLEMENTATION MODULE RealConversions;
 				END;
 			END;
 		END;
+		IF (NOT ecvtflag) AND (ind1 = 0) THEN
+			str[0] := CHR(ORD(str[0])-5);
+			INC(ind1);
+		END;
 	END;
 	IF ecvtflag THEN
 		FOR i := ind1 TO 2 BY -1 DO
@@ -169,8 +173,13 @@ IMPLEMENTATION MODULE RealConversions;
 		END;
 		IF ndigits = 0 THEN
 			str[pointpos] := 0C;
+			ind1 := pointpos - 1;
 		ELSE
 			str[pointpos] := '.';
+			IF INTEGER(ind1) > pointpos+INTEGER(ndigits) THEN
+				ind1 := pointpos+INTEGER(ndigits);
+			END;
+			str[pointpos+INTEGER(ndigits)+1] := 0C;
 		END;
 		IF sign THEN
 			FOR i := ind1 TO 0 BY -1 DO
diff --git a/lang/m2/libm2/random.mod b/lang/m2/libm2/random.mod
index db8225626..487b47b14 100644
--- a/lang/m2/libm2/random.mod
+++ b/lang/m2/libm2/random.mod
@@ -12,15 +12,16 @@ IMPLEMENTATION MODULE random;
 *)
 
 FROM Unix IMPORT getpid, time;
-TYPE index = [0..54];
+TYPE index = [1..55];
 
 VAR	X: ARRAY index OF CARDINAL;
-	k, j: index;
+	j, k: index;
+	tm: LONGINT;
 
 PROCEDURE Random(): CARDINAL;
 BEGIN
-	IF k+1 > 54 THEN k := 0; ELSE INC(k) END;
-	IF j+1 > 54 THEN j := 0; ELSE INC(j) END;
+	IF k-1 <= 0 THEN k := 55; ELSE DEC(k) END;
+	IF j-1 <= 0 THEN j := 55; ELSE DEC(j) END;
 	X[k] := X[k] + X[j];
 	RETURN X[k]
 END Random;
@@ -32,16 +33,26 @@ BEGIN
 END Uniform;
 
 PROCEDURE StartSeed(seed: CARDINAL);
+VAR v: CARDINAL;
 BEGIN
-	X[0] := seed;
-	FOR k := 1 TO 54 DO
-		X[k] := X[k-1] * 1297;
+	FOR k := 1 TO 55 DO
+		seed := 1297 * seed + 123;
+		X[k] := seed;
 	END;
-	k := 54;
-	j := 30;
+	FOR k := 1 TO 15 DO
+		j := tm MOD 55D + 1D;
+		v := X[j];
+		tm := tm DIV 7D;
+		j := tm MOD 55D + 1D;
+		X[j] := v;
+		tm := tm * 3D;
+	END;
+	k := 1;
+	j := 25;
 END StartSeed;
 
 BEGIN
- 	X[0] := time(NIL);
-	StartSeed(CARDINAL(getpid()) * X[0]);
+ 	tm := time(NIL);
+	X[1] := tm;
+	StartSeed(CARDINAL(getpid()) * X[1]);
 END random.
-- 
2.34.1