Merge branch 'master' into 12101210

1 files changed, 30 insertions, 0 deletions

diff --git a/js/src/tests/test262/language/expressions/coalesce/tco-pos-undefined-strict.js b/js/src/tests/test262/language/expressions/coalesce/tco-pos-undefined-strict.js
new file mode 100644
index 0000000000..70f6ff59ec
--- /dev/null
+++ b/js/src/tests/test262/language/expressions/coalesce/tco-pos-undefined-strict.js
@@ -0,0 +1,30 @@
+// |reftest| skip -- tail-call-optimization is not supported
+'use strict';
+// Copyright (C) 2019 Leo Balter. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+
+/*---
+description: Expression is a candidate for tail-call optimization.
+esid: sec-static-semantics-hascallintailposition
+info: |
+  Expression Rules
+
+  CoalesceExpression : CoalesceExpressionHead ?? BitwiseORExpression
+
+  1. Return HasCallInTailPosition of BitwiseORExpression with argument call.
+flags: [onlyStrict]
+features: [tail-call-optimization, coalesce-expression]
+includes: [tcoHelper.js]
+---*/
+
+var callCount = 0;
+(function f(n) {
+  if (n === 0) {
+    callCount += 1
+    return;
+  }
+  return undefined ?? f(n - 1);
+}($MAX_ITERATIONS));
+assert.sameValue(callCount, 1);
+
+reportCompare(0, 0);