From c4a35020f1838b7cdf091f9a72c7d540b1596a95 Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Mon, 2 Nov 2015 14:39:10 +0000
Subject: [PATCH 1/4] Add event to get last read receipt for a user.

---
 lib/models/room.js | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/lib/models/room.js b/lib/models/room.js
index da4d1f1b6..f0f7e271b 100644
--- a/lib/models/room.js
+++ b/lib/models/room.js
@@ -321,6 +321,21 @@ Room.prototype.getUsersReadUpTo = function(event) {
     });
 };
 
+/**
+ * Get the ID of the event that a given user has read up to, or null if we
+ * have received no read receipts from them.
+ * @param {String} user ID to get read receipt event ID for
+ * @return {String} ID of the latest event that the given user has read, or null.
+ * an empty list.
+ */
+Room.prototype.getEventReadUpTo = function(userId) {
+    if (this._receipts === undefined || this._receipts['m.read'] === undefined) {
+        return null;
+    }
+
+    return this._receipts['m.read'][userId].eventId;
+};
+
 /**
  * Get a list of receipts for the given event.
  * @param {MatrixEvent} event the event to get receipts for

From 4adc5f2c85c98ce53c0505961c8ba972204d5fad Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Mon, 2 Nov 2015 15:19:29 +0000
Subject: [PATCH 2/4] Also need to check if the event is null

---
 lib/models/room.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/lib/models/room.js b/lib/models/room.js
index f0f7e271b..03df2fa55 100644
--- a/lib/models/room.js
+++ b/lib/models/room.js
@@ -329,7 +329,11 @@ Room.prototype.getUsersReadUpTo = function(event) {
  * an empty list.
  */
 Room.prototype.getEventReadUpTo = function(userId) {
-    if (this._receipts === undefined || this._receipts['m.read'] === undefined) {
+    if (
+        this._receipts === undefined ||
+        this._receipts['m.read'] === undefined ||
+        this._receipts['m.read'][userId] === undefined
+    ) {
         return null;
     }
 

From 083dde35578fa8045dde22e19cdd42ba867266c8 Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Mon, 2 Nov 2015 16:00:40 +0000
Subject: [PATCH 3/4] Fix doc

---
 lib/models/room.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/models/room.js b/lib/models/room.js
index 03df2fa55..052ff19a8 100644
--- a/lib/models/room.js
+++ b/lib/models/room.js
@@ -324,7 +324,7 @@ Room.prototype.getUsersReadUpTo = function(event) {
 /**
  * Get the ID of the event that a given user has read up to, or null if we
  * have received no read receipts from them.
- * @param {String} user ID to get read receipt event ID for
+ * @param {String} userId The user ID to get read receipt event ID for
  * @return {String} ID of the latest event that the given user has read, or null.
  * an empty list.
  */

From 1b43bc78d06c9403c6e57cbc538f127100327aef Mon Sep 17 00:00:00 2001
From: David Baker <dave@matrix.org>
Date: Mon, 2 Nov 2015 16:02:48 +0000
Subject: [PATCH 4/4] Remove unnecessary null check & s/"/'/

---
 lib/models/room.js | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/lib/models/room.js b/lib/models/room.js
index 052ff19a8..3676b9e8d 100644
--- a/lib/models/room.js
+++ b/lib/models/room.js
@@ -330,14 +330,13 @@ Room.prototype.getUsersReadUpTo = function(event) {
  */
 Room.prototype.getEventReadUpTo = function(userId) {
     if (
-        this._receipts === undefined ||
-        this._receipts['m.read'] === undefined ||
-        this._receipts['m.read'][userId] === undefined
+        this._receipts["m.read"] === undefined ||
+        this._receipts["m.read"][userId] === undefined
     ) {
         return null;
     }
 
-    return this._receipts['m.read'][userId].eventId;
+    return this._receipts["m.read"][userId].eventId;
 };
 
 /**