Fix for issue #101

Author: peterolson

BigInteger.js

@@ -1038,14 +1038,31 @@ var bigInt = (function (undefined) {
     }
     var parseBase = function (text, base) {
         var length = text.length;
+		var i;
+		var absBase = Math.abs(base);
+		for(var i = 0; i < length; i++) {
+			var c = text[i].toLowerCase();
+			if(c === "-") continue;
+			if(/[a-z0-9]/.test(c)) {
+			    if(/[0-9]/.test(c) && +c >= absBase) {
+					if(c === "1" && absBase === 1) continue;
+                    throw new Error(c + " is not a valid digit in base " + base + ".");
+				} else if(c.charCodeAt(0) - 87 >= absBase) {
+					throw new Error(c + " is not a valid digit in base " + base + ".");
+				}
+			}
+		}
         if (2 <= base && base <= 36) {
             if (length <= LOG_MAX_INT / Math.log(base)) {
+				var result = parseInt(text, base);
+				if(isNaN(result)) {
+					throw new Error(c + " is not a valid digit in base " + base + ".");
+				}
                 return new SmallInteger(parseInt(text, base));
             }
         }
         base = parseValue(base);
         var digits = [];
-        var i;
         var isNegative = text[0] === "-";
         for (i = isNegative ? 1 : 0; i < text.length; i++) {
             var c = text[i].toLowerCase(),