From 1d7081d1e4b405f6acae9a35733a0193ed0370aa Mon Sep 17 00:00:00 2001
From: Fedor <fedor@mail.ru>
Date: Wed, 9 Sep 2020 17:29:54 +0300
Subject: [PATCH] Improve resilience of AbortSignals.

---
 dom/abort/AbortSignal.cpp | 9 ++++++++-
 dom/abort/moz.build       | 2 +-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/dom/abort/AbortSignal.cpp b/dom/abort/AbortSignal.cpp
index 20f36d2ab..7ee6c49a9 100644
--- a/dom/abort/AbortSignal.cpp
+++ b/dom/abort/AbortSignal.cpp
@@ -56,9 +56,16 @@ AbortSignal::Aborted() const
 void
 AbortSignal::Abort()
 {
-  MOZ_ASSERT(!mAborted);
+  // Re-entrancy guard
+  if (mAborted) {
+    return;
+  }
   mAborted = true;
 
+  // We might be deleted as a result of aborting a follower, so ensure we
+  // stay alive until all followers have been aborted.
+  RefPtr<AbortSignal> pinThis = this;
+
   // Let's inform the followers.
   for (uint32_t i = 0; i < mFollowers.Length(); ++i) {
     mFollowers[i]->Aborted();
diff --git a/dom/abort/moz.build b/dom/abort/moz.build
index cb48ee15f..eacc9ddc7 100644
--- a/dom/abort/moz.build
+++ b/dom/abort/moz.build
@@ -14,7 +14,7 @@ EXPORTS.mozilla.dom += [
     'AbortSignal.h',
 ]
 
-UNIFIED_SOURCES += [
+SOURCES += [
     'AbortController.cpp',
     'AbortSignal.cpp',
 ]