From 0be888ca96b044285767b2a570d8cf05666e68b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Hru=C5=A1ka?= <ondra@ondrovo.com>
Date: Fri, 7 Jul 2017 08:27:52 +0200
Subject: [PATCH] Fix back button to never go to a different website using
 history len check

---
 app/javascript/mastodon/components/column_back_button.js  | 8 ++++++--
 .../mastodon/components/column_back_button_slim.js        | 8 ++++++--
 app/javascript/mastodon/components/column_header.js       | 8 ++++++--
 app/javascript/mastodon/main.js                           | 5 +++++
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/app/javascript/mastodon/components/column_back_button.js b/app/javascript/mastodon/components/column_back_button.js
index ba2736d7a0..589215ce80 100644
--- a/app/javascript/mastodon/components/column_back_button.js
+++ b/app/javascript/mastodon/components/column_back_button.js
@@ -9,8 +9,12 @@ export default class ColumnBackButton extends React.PureComponent {
   };
 
   handleClick = () => {
-    if (window.history && window.history.length === 1) this.context.router.history.push('/');
-    else this.context.router.history.goBack();
+    // if history is exhausted, or we would leave mastodon, just go to root.
+    if (window.history && (window.history.length === 1 || window.history.length === window._mastoInitialHistoryLen)) {
+      this.context.router.history.push('/');
+    } else {
+      this.context.router.history.goBack();
+    }
   }
 
   render () {
diff --git a/app/javascript/mastodon/components/column_back_button_slim.js b/app/javascript/mastodon/components/column_back_button_slim.js
index 3b4f46d99f..2cdf1b25b1 100644
--- a/app/javascript/mastodon/components/column_back_button_slim.js
+++ b/app/javascript/mastodon/components/column_back_button_slim.js
@@ -9,8 +9,12 @@ export default class ColumnBackButtonSlim extends React.PureComponent {
   };
 
   handleClick = () => {
-    if (window.history && window.history.length === 1) this.context.router.history.push('/');
-    else this.context.router.history.goBack();
+    // if history is exhausted, or we would leave mastodon, just go to root.
+    if (window.history && (window.history.length === 1 || window.history.length === window._mastoInitialHistoryLen)) {
+      this.context.router.history.push('/');
+    } else {
+      this.context.router.history.goBack();
+    }
   }
 
   render () {
diff --git a/app/javascript/mastodon/components/column_header.js b/app/javascript/mastodon/components/column_header.js
index ec9379320f..027d017675 100644
--- a/app/javascript/mastodon/components/column_header.js
+++ b/app/javascript/mastodon/components/column_header.js
@@ -45,8 +45,12 @@ export default class ColumnHeader extends React.PureComponent {
   }
 
   handleBackClick = () => {
-    if (window.history && window.history.length === 1) this.context.router.history.push('/');
-    else this.context.router.history.goBack();
+    // if history is exhausted, or we would leave mastodon, just go to root.
+    if (window.history && (window.history.length === 1 || window.history.length === window._mastoInitialHistoryLen)) {
+      this.context.router.history.push('/');
+    } else {
+      this.context.router.history.goBack();
+    }
   }
 
   handleTransitionEnd = () => {
diff --git a/app/javascript/mastodon/main.js b/app/javascript/mastodon/main.js
index 02e0f56f95..f14b6a8253 100644
--- a/app/javascript/mastodon/main.js
+++ b/app/javascript/mastodon/main.js
@@ -26,6 +26,11 @@ function main() {
 
     ReactDOM.render(<Mastodon {...props} />, mountNode);
     perf.stop('main()');
+
+    // remember the initial URL
+    if (window.history && typeof window._mastoInitialHistoryLen === 'undefined') {
+      window._mastoInitialHistoryLen = window.history.length;
+    }
   });
 }