From 7db7a311f16a58e56fd798f63e480c59b91f01b8 Mon Sep 17 00:00:00 2001
From: Elias Nahum <nahumhbl@gmail.com>
Date: Tue, 24 Apr 2018 08:01:55 -0300
Subject: [PATCH] MM-10300 Fix crash when leaving channel (#1606)

---
 app/actions/views/channel.js | 20 ++++++++++++++++----
 app/constants/view.js        |  1 +
 app/reducers/views/team.js   | 23 +++++++++++++++++++++++
 3 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/app/actions/views/channel.js b/app/actions/views/channel.js
index b6adc19c3..20238c9ee 100644
--- a/app/actions/views/channel.js
+++ b/app/actions/views/channel.js
@@ -400,11 +400,23 @@ export function refreshChannelWithRetry(channelId) {
 
 export function leaveChannel(channel, reset = false) {
     return async (dispatch, getState) => {
-        const {currentTeamId} = getState().entities.teams;
-        await serviceLeaveChannel(channel.id)(dispatch, getState);
-        if (channel.isCurrent || reset) {
-            await selectInitialChannel(currentTeamId)(dispatch, getState);
+        const state = getState();
+        const {currentChannelId} = state.entities.channels;
+        const {currentTeamId} = state.entities.teams;
+
+        dispatch({
+            type: ViewTypes.REMOVE_LAST_CHANNEL_FOR_TEAM,
+            data: {
+                teamId: currentTeamId,
+                channelId: channel.id,
+            },
+        });
+
+        if (channel.id === currentChannelId || reset) {
+            await dispatch(selectInitialChannel(currentTeamId));
         }
+
+        await serviceLeaveChannel(channel.id)(dispatch, getState);
     };
 }
 
diff --git a/app/constants/view.js b/app/constants/view.js
index 471e823b1..5f53b7a36 100644
--- a/app/constants/view.js
+++ b/app/constants/view.js
@@ -44,6 +44,7 @@ const ViewTypes = keyMirror({
     SET_CHANNEL_DISPLAY_NAME: null,
 
     SET_LAST_CHANNEL_FOR_TEAM: null,
+    REMOVE_LAST_CHANNEL_FOR_TEAM: null,
 
     GITLAB: null,
     SAML: null,
diff --git a/app/reducers/views/team.js b/app/reducers/views/team.js
index 47f0ff97a..1ddfdf415 100644
--- a/app/reducers/views/team.js
+++ b/app/reducers/views/team.js
@@ -44,6 +44,29 @@ function lastChannelForTeam(state = {}, action) {
             [action.teamId]: channelIds,
         };
     }
+    case ViewTypes.REMOVE_LAST_CHANNEL_FOR_TEAM: {
+        const {data} = action;
+        const team = state[data.teamId];
+
+        if (!data.channelId) {
+            return state;
+        }
+
+        if (team) {
+            const channelIds = [...team];
+            const index = channelIds.indexOf(data.channelId);
+            if (index !== -1) {
+                channelIds.splice(index, 1);
+            }
+
+            return {
+                ...state,
+                [data.teamId]: channelIds,
+            };
+        }
+
+        return state;
+    }
     default:
         return state;
     }