Fix bug #40: string.sub broken for j=0 or j<i

gamesys · Jul 10, 2017 · d3f70d8 · d3f70d8
1 parent ddec86a
commit d3f70d8
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/vm/src/lib.js b/vm/src/lib.js
@@ -1924,7 +1924,7 @@
 			if (typeof s != 'string' && typeof s != 'number') throw new shine.Error("Bad argument #1 to 'sub' (string expected, got " + typeof s + ")");
 			s = '' + s;
 			i = i || 1;
-			j = j || s.length;
+			if (j === undefined) j = s.length;
 
 			if (i > 0) {
 				i = i - 1;
@@ -1933,6 +1933,7 @@
 			}
 
 			if (j < 0) j = s.length + j + 1;
+			if (i > j) return '';
 
 			return s.substring(i, j);
 		},