--- hatari/src/debug/evaluate.c	2019/04/09 08:53:04	1.1.1.3
+++ hatari/src/debug/evaluate.c	2019/04/09 08:54:22	1.1.1.4
@@ -1,7 +1,7 @@
 /*
-  Hatari - calculate.c
+  Hatari - evaluate.c
 
-  Copyright (C) 1994, 2009-2010 by Eero Tamminen
+  Copyright (C) 1994, 2009-2014 by Eero Tamminen
 
   This file is distributed under the GNU General Public License, version 2
   or at your option any later version. Read the file gpl.txt for details.
@@ -158,7 +158,7 @@ static int getNumber(const char *str, Ui
 		}
 		str += 2;
 	}
-	else if (!isxdigit(str[0])) {
+	else if (!isxdigit((unsigned char)str[0])) {
 
 		/* doesn't start with (hex) number -> is it prefix? */
 		switch (*str++) {
@@ -206,8 +206,8 @@ static int getValue(const char *str, Uin
 	Uint32 mask, *addr;
 	int len;
 
-	for (end = str; *end == '_' || isalnum(*end); end++);
-	
+	for (end = str; *end == '_' || isalnum((unsigned char)*end); end++);
+
 	len = end-str;
 	if (len >= (int)sizeof(name)) {
 		fprintf(stderr, "ERROR: symbol name at '%s' too long (%d chars)\n", str, len);
@@ -314,7 +314,10 @@ bool Eval_Number(const char *str, Uint32
 	 * addition to numbers.
 	 */
 	offset = getNumber(str, number, &base);
-	return isNumberOK(str, offset, base);
+	if (!offset)
+		return false;
+	else
+		return isNumberOK(str, offset, base);
 }
 
 
@@ -343,7 +346,7 @@ int Eval_Range(char *str1, Uint32 *lower
 	}
 
 	offset = getValue(str1, lower, &base, fordsp);
-	if (!isNumberOK(str1, offset, base)) {
+	if (offset == 0 || !isNumberOK(str1, offset, base)) {
 		/* first number not OK */
 		fprintf(stderr,"Invalid address value '%s'!\n", str1);
 		ret = -1;
@@ -353,7 +356,7 @@ int Eval_Range(char *str1, Uint32 *lower
 	}
 	if (fDash) {
 		offset = getValue(str2, upper, &base, fordsp);
-		if (!isNumberOK(str2, offset, base)) {
+		if (offset == 0 || !isNumberOK(str2, offset, base)) {
 			/* second number not OK */
 			fprintf(stderr, "Invalid address value '%s'!\n", str2);
 			ret = -1;
@@ -689,7 +692,7 @@ static long long apply_op (char opcode,
 /* ==================================================================== */
 
 /**
- * open prenthesis, push values & operators to stack
+ * open parenthesis, push values & operators to stack
  */
 static void open_bracket (void)
 {
@@ -706,7 +709,7 @@ static void open_bracket (void)
 
 /* -------------------------------------------------------------------- */
 /**
- * close prenthesis, and evaluate / pop stacks
+ * close parenthesis, and evaluate / pop stacks
  */
 /* last parsed value, last param. flag, trigonometric mode	*/
 static long long close_bracket (long long value)
@@ -714,7 +717,7 @@ static long long close_bracket (long lon
 	/* returns the value of the parenthesised expression	*/
 
 	if (id.valid) {			/* preceded by an operator	*/
-		if (par.idx > 0) {	/* prenthesis has a pair	*/
+		if (par.idx > 0) {	/* parenthesis has a pair	*/
 			Uint32 addr;
 
 			/* calculate the value of parenthesised exp.	*/