document DATA-PRESENT in CHANGELOG

I wonder where else this could be documented? It's kind of a niche
feature, since it needs at least a partial custom implementation of the p2p
protocol or the p2phttp protocol. But it can save a lot of bandwidth and
avoid the proxy needing disk space to buffer files uploaded to a special
remote.

diff --git a/CHANGELOG b/CHANGELOG
index 293e9f4a8f01bd9ca9703389628afbe6f71a36cd..f3aa278e30c3ed48b181f1ceda3d2edd86b4527b 100644 (file)
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -16,6 +16,13 @@ git-annex (10.20240928) UNRELEASED; urgency=medium
     remotes, leading to protocol error messages involving "GITMANIFEST".
   * adjust: Allow any order of options when combining --hide-missing with
     options like --unlock.
+  * Support P2P protocol version 4. This allows DATA-PRESENT to be sent
+    after PUT (and in the HTTP P2P protocol, v4/put has a data-present
+    parameter). When used with a proxy to a special remote like a S3
+    bucket, this allows a custom client to upload content to S3 itself,
+    and then use the P2P protocol to inform the proxy that the content has
+    been stored there, which will result in the same git-annex branch state
+    updates as sending DATA via the proxy.
 
  -- Joey Hess <id@joeyh.name>  Thu, 17 Oct 2024 11:02:17 -0400