Bug 1352827: Handle potential null reference during cleanup by CC. r=hsivonen
MozReview-Commit-ID: G7BM3nuEKY1
--- a/dom/base/nsDocument.cpp
+++ b/dom/base/nsDocument.cpp
@@ -10572,24 +10572,28 @@ public:
MaybeUnblockParser();
mPromise->MaybeReject(aCx, aValue);
}
protected:
virtual ~UnblockParsingPromiseHandler()
{
- MaybeUnblockParser();
+ // If we're being cleaned up by the cycle collector, our mDocument reference
+ // may have been unlinked while our mParser weak reference is still alive.
+ if (mDocument) {
+ MaybeUnblockParser();
+ }
}
private:
void MaybeUnblockParser() {
nsCOMPtr<nsIParser> parser = do_QueryReferent(mParser);
if (parser) {
- MOZ_ASSERT(mDocument);
+ MOZ_DIAGNOSTIC_ASSERT(mDocument);
nsCOMPtr<nsIParser> docParser = mDocument->CreatorParserOrNull();
if (parser == docParser) {
parser->UnblockParser();
parser->ContinueInterruptedParsingAsync();
}
}
mParser = nullptr;
mDocument = nullptr;
--- a/dom/base/test/test_blockParsing.html
+++ b/dom/base/test/test_blockParsing.html
@@ -76,13 +76,56 @@ add_task(function* () {
yield runTest("http://mochi.test:8888/chrome/dom/base/test/file_external_script.html",
'<html lang="en"></html>',
'<html lang="en"><head>\n <script src="file_script.js"><\/script>\n <meta charset="utf-8">\n <title></title>\n</head>\n<body>\n <p>Hello Mochitest</p>\n\n\n</body></html>');
yield runTest("http://mochi.test:8888/chrome/dom/base/test/file_external_script.xhtml",
'<html xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"></html>',
'<html xml:lang="en" xmlns="http://www.w3.org/1999/xhtml">\n<head>\n <script src="file_script.js"><\/script>\n <title></title>\n</head>\n<body>\n <p>Hello Mochitest</p>\n</body>\n</html>');
});
+
+add_task(function* test_cleanup() {
+ const TOPIC = "blocking-promise-destroyed";
+
+ const finalizationWitness = Components.classes["@mozilla.org/toolkit/finalizationwitness;1"]
+ .getService(Components.interfaces.nsIFinalizationWitnessService);
+
+ for (let url of ["http://mochi.test:8888/chrome/dom/base/test/file_inline_script.html",
+ "http://mochi.test:8888/chrome/dom/base/test/file_inline_script.xhtml"]) {
+ let iframe = document.createElement("iframe");
+ iframe.src = url;
+
+ // Create a promise that never resolves.
+ let blockerPromise = new Promise(() => {});
+
+ // Create a finalization witness so we can be sure that the promises
+ // have been collected before the end of the test.
+ let destroyedPromise = TestUtils.topicObserved(TOPIC);
+ let witness = finalizationWitness.make(TOPIC, url);
+ blockerPromise.witness = witness;
+
+ let insertedPromise = TestUtils.topicObserved("document-element-inserted", document => {
+ document.blockParsing(blockerPromise).witness = witness;
+
+ return true;
+ });
+
+ document.body.appendChild(iframe);
+ yield insertedPromise;
+
+ // Clear the promise reference, destroy the document, and force GC/CC. This should
+ // trigger any potential leaks or cleanup issues.
+ blockerPromise = null;
+ witness = null;
+ iframe.remove();
+
+ Components.utils.forceGC();
+ Components.utils.forceCC();
+ Components.utils.forceGC();
+
+ // Make sure the blocker promise has been collected.
+ let [, data] = yield destroyedPromise;
+ is(data, url, "Should have correct finalizer URL");
+ }
+});
</script>
</body>
</html>
-
-