From 13c7f55a793974b05a2b343547330e873a89d75a Mon Sep 17 00:00:00 2001
From: Bruno Windels <brunow@element.io>
Date: Wed, 4 Nov 2020 16:01:25 +0100
Subject: [PATCH] split up setKey and setKeyAndQueue

as dehydrating in the background prevents use-cases where you
want to await the creation of the dehydrated device
---
 src/client.js             |  2 +-
 src/crypto/dehydration.ts | 18 +++++++++++++++---
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/src/client.js b/src/client.js
index 3f2ac2c66..837122c35 100644
--- a/src/client.js
+++ b/src/client.js
@@ -577,7 +577,7 @@ MatrixClient.prototype.setDehydrationKey = async function(
         logger.warn('not dehydrating device if crypto is not enabled');
         return;
     }
-    return await this._crypto._dehydrationManager.setDehydrationKey(
+    return await this._crypto._dehydrationManager.setKeyAndQueue(
         key, keyInfo, deviceDisplayName,
     );
 };
diff --git a/src/crypto/dehydration.ts b/src/crypto/dehydration.ts
index f9996c583..e276c140c 100644
--- a/src/crypto/dehydration.ts
+++ b/src/crypto/dehydration.ts
@@ -77,10 +77,23 @@ export class DehydrationManager {
             },
         );
     }
-    async setDehydrationKey(
+
+    /** set the key, and queue periodic dehydration to the server in the background */
+    async setKeyAndQueueDehydration(
         key: Uint8Array, keyInfo: {[props: string]: any} = {},
         deviceDisplayName: string = undefined,
     ): Promise<void> {
+        const matches = await this.setKey(key, keyInfo, deviceDisplayName);
+        if (!matches) {
+            // start dehydration in the background
+            this.dehydrateDevice();
+        }
+    }
+
+    async setKey(
+        key: Uint8Array, keyInfo: {[props: string]: any} = {},
+        deviceDisplayName: string = undefined,
+    ): Promise<boolean> {
         if (!key) {
             // unsetting the key -- cancel any pending dehydration task
             if (this.timeoutId) {
@@ -116,9 +129,8 @@ export class DehydrationManager {
             this.key = key;
             this.keyInfo = keyInfo;
             this.deviceDisplayName = deviceDisplayName;
-            // start dehydration in the background
-            this.dehydrateDevice();
         }
+        return matches;
     }
     private async dehydrateDevice(): Promise<void> {
         if (this.inProgress) {