1 files changed, 52 insertions, 0 deletions
diff --git a/LayoutTests/fast/js/resources/string-concatenate-outofmemory.js b/LayoutTests/fast/js/resources/string-concatenate-outofmemory.js
new file mode 100644
index 0000000..db962e8
--- /dev/null
+++ b/LayoutTests/fast/js/resources/string-concatenate-outofmemory.js
@@ -0,0 +1,52 @@
+description(
+'This test checks if repeated string concatenation causes an exception (and not a crash). From WebKit Bug <a href="http://bugs.webkit.org/show_bug.cgi?id=11131">Repeated string concatenation results in OOM crash</a>.'
+);
+
+shouldThrow('s = "a"; while (1) { s += s; }', '"Error: Out of memory"'); // Expand at end of string
+shouldThrow('s = "a"; while (1) { s += ("a" + s); }', '"Error: Out of memory"'); // Expand at beginning of string
+shouldThrow('s = "a"; while (1) { s = [s, s].join(); }', '"Error: Out of memory"'); // Expand using UString::append.
+
+debug('');
+debug(
+'We also verify that the the string is stil functional after the out of memory exception is raised.  In <a href="rdar://problem/5352887">rdar://problem/5352887</a>, accessing the string after the exception would crash.'
+);
+
+function ensureStringIsUsable(testName, stringName, str) {
+    str[str.length - 1];
+    try { [str, str].join(str); } catch (o) { }
+    try { "a" + str; } catch (o) { }
+    try { str + "a"; } catch (o) { }
+    debug('PASS: String ' + stringName + ' was functional after ' + testName + ' raised out of memory exception.');
+}
+
+var s = "a";
+try {
+    while (1)
+        s += s; // This will expand the string at the end using UString::expandCapacity
+} catch (o) {
+    ensureStringIsUsable('expandCapacity', 's', s);
+}
+
+s = "a";
+var t = "";
+try {
+    while (1) {
+        t = "a" + s;
+        s += t; // This will expand the string at the beginning using UString::expandPreCapacity
+    }
+} catch (o) {
+    // Ensure both strings involved are unharmed
+    ensureStringIsUsable('expandPreCapacity', 's', s);
+    ensureStringIsUsable('expandPreCapacity', 't', t);
+}
+delete t;
+
+s = "a";
+try {
+    while (1)
+        s = [s, s].join(); // This will expand the string using UString::append.
+} catch (o) {
+    ensureStringIsUsable('append', 's', s);
+}
+
+var successfullyParsed = true;