From ffb1e76d8b00bdac5de662ea3d24f8f8fbf32065 Mon Sep 17 00:00:00 2001
From: Ivan Enderlin <ivan@mnt.io>
Date: Tue, 23 Jun 2026 18:48:35 +0200
Subject: [PATCH] doc(sdk): Add the changelog file.

---
 crates/matrix-sdk/changelog.d/6684.fixed.md | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 crates/matrix-sdk/changelog.d/6684.fixed.md

diff --git a/crates/matrix-sdk/changelog.d/6684.fixed.md b/crates/matrix-sdk/changelog.d/6684.fixed.md
new file mode 100644
index 000000000..feea3fe8f
--- /dev/null
+++ b/crates/matrix-sdk/changelog.d/6684.fixed.md
@@ -0,0 +1,7 @@
+Ensure a `VectorDiff` is not emitted to subscribers when an event cache is
+shrunk because no subscribers is listening to it. If there is no subscribers,
+it's useless to send it anyway, and if in the future, a race happens and a
+subscriber exists, it must not receive this diff.
+
+At the same time, the way the subscribers are tracked and counted have been
+revisited to use less space in memory and use less atomic operations.