set capacity for StringBuilder in String#repeat

mozilla · May 8, 2015 · 90cb55d · 90cb55d
1 parent 1ac0c75
commit 90cb55d
Showing 1 changed file with 6 additions and 1 deletion.
diff --git a/src/org/mozilla/javascript/NativeString.java b/src/org/mozilla/javascript/NativeString.java
@@ -467,7 +467,12 @@ public Object execIdCall(IdFunctionObject f, Context cx, Scriptable scope,
 
                     if (cnt < 0 || cnt == Double.POSITIVE_INFINITY) throw rangeError("Invalid count value");
 
-                    StringBuilder retval = new StringBuilder("");
+                    long size = str.length() * (long) cnt;
+                    // Check for overflow
+                    if (size >= Integer.MAX_VALUE) {
+                        size = Integer.MAX_VALUE;
+                    }
+                    StringBuilder retval = new StringBuilder((int) size);
                     while (cnt-- > 0) retval.append(str);
                     return retval.toString();
                 }