matrix-js-sdk@31.0.0.patch

diff --git a/lib/crypto/index.js b/lib/crypto/index.js
index b965c8c5bd8b6eb939c2f449a82e22fd83996369..be9560d26d73e671f84104c9c465ba50dc4a4f82 100644
--- a/lib/crypto/index.js
+++ b/lib/crypto/index.js
@@ -1901,10 +1901,14 @@ class Crypto extends _typedEventEmitter.TypedEventEmitter {
     }
     const res = await this.baseApis.uploadKeysRequest(requestBody);
     if (fallbackJson) {
-      this.fallbackCleanup = setTimeout(() => {
+      let timer = setTimeout(() => {
         delete this.fallbackCleanup;
         this.olmDevice.forgetOldFallbackKey();
       }, 60 * 60 * 1000);
+      if (typeof timer.unref === "function") {
+        timer.unref();
+      }
+      this.fallbackCleanup = timer;
     }
     await this.olmDevice.markKeysAsPublished();
     return res;
diff --git a/lib/http-api/utils.js b/lib/http-api/utils.js
index 9115598fd769bad15ed23293a68d617d5dbf21a5..95c28e59d8414dbc0837f5c85c98dd96a80446c8 100644
--- a/lib/http-api/utils.js
+++ b/lib/http-api/utils.js
@@ -30,9 +30,12 @@ limitations under the License.
 // Ponyfill for https://developer.mozilla.org/en-US/docs/Web/API/AbortSignal/timeout
 function timeoutSignal(ms) {
   const controller = new AbortController();
-  setTimeout(() => {
+  let timer = setTimeout(() => {
     controller.abort();
   }, ms);
+  if (typeof timer.unref === 'function') {
+    timer.unref();
+  }
   return controller.signal;
 }
 function anySignal(signals) {
diff --git a/lib/sync.js b/lib/sync.js
index f59265e1089ce832c0be8a23aa19813c2d4738cc..e9b70f2b75a89bb561fc420f03b5106a55f34e09 100644
--- a/lib/sync.js
+++ b/lib/sync.js
@@ -747,6 +747,13 @@ class SyncApi {
         nextSyncToken: data.next_batch,
         catchingUp: this.catchingUp
       };
+
+      if (syncToken === data.next_batch) {
+        // there are no updates and we are just idle--wait before 
+        // continuing so that idle syncs don't DDoS the server
+        await new Promise(r => setTimeout(r, 1000));
+      }
+
       if (this.syncOpts.crypto) {
         // tell the crypto module we're about to process a sync
         // response