From f3b7fcb560be30b0bce2bea440fb6d0a947b444f Mon Sep 17 00:00:00 2001
From: roytam1 <roytam@gmail.com>
Date: Fri, 24 Apr 2026 10:22:58 +0800
Subject: [PATCH] import from UXP: [network] Hold strong ref in
 `nsSyncStreamListener::Available`. (68fd6722)

---
 netwerk/base/nsSyncStreamListener.cpp | 22 ++++++++++++++--------
 1 file changed, 14 insertions(+), 8 deletions(-)

diff --git a/netwerk/base/nsSyncStreamListener.cpp b/netwerk/base/nsSyncStreamListener.cpp
index e80e885c5..86901aa62 100644
--- a/netwerk/base/nsSyncStreamListener.cpp
+++ b/netwerk/base/nsSyncStreamListener.cpp
@@ -122,16 +122,22 @@ nsSyncStreamListener::Close()
 NS_IMETHODIMP
 nsSyncStreamListener::Available(uint64_t *result)
 {
-    if (NS_FAILED(mStatus))
-        return mStatus;
+  // Nested event loop can run code that drops the last external reference.
+  RefPtr<nsSyncStreamListener> self(this);
 
-    mStatus = mPipeIn->Available(result);
-    if (NS_SUCCEEDED(mStatus) && (*result == 0) && !mDone) {
-        mStatus = WaitForData();
-        if (NS_SUCCEEDED(mStatus))
-            mStatus = mPipeIn->Available(result);
-    }
+  if (NS_FAILED(mStatus)) {
     return mStatus;
+  }
+
+  mStatus = mPipeIn->Available(result);
+  if (NS_SUCCEEDED(mStatus) && (*result == 0) && !mDone) {
+    mStatus = WaitForData();
+    if (NS_SUCCEEDED(mStatus)) {
+      mStatus = mPipeIn->Available(result);
+    }
+  }
+
+  return mStatus;
 }
 
 NS_IMETHODIMP