Fix bad type-inferrence for logical expressions.

tests/language/logical_expression3_test.dart

Index: tests/language/logical_expression3_test.dart
diff --git a/tests/language/logical_expression3_test.dart b/tests/language/logical_expression3_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..2a90d70ba672871c4b495dc86c4064a3ed0c1072
--- /dev/null
+++ b/tests/language/logical_expression3_test.dart
@@ -0,0 +1,29 @@
+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import "package:expect/expect.dart";
+
+bool nonInlinedNumTypeCheck(Object object) {
+  if (new DateTime.now().millisecondsSinceEpoch == 42) {
+    return nonInlinedNumTypeCheck(object);
+  }
+  return object is num;
+}
+
+int confuse(x) {
+  if (new DateTime.now().millisecondsSinceEpoch == 42) return confuse(x - 1);
+  return x;
+}
+
+main() {
+  var o = [ "foo", 499 ][confuse(0)];
+
+  // When the lhs of a logical or fails, it must not assume that all negative is
+  // checks in it, have failed.
+  // Here, the `o is! num` check succeeds, but the length test failed.
+  if ((o is! num && o.length == 4) ||
+      (nonInlinedNumTypeCheck(o))) {
+    Expect.fail("Type-check failed");
+  }
+}