[MM-31626] bypass gitlab browser-check for oauth login (#1439)

* MM-31626 make User Agent configurable by user

* add info

* remove chrome from UA for gitlab.com

* remove previous solution

Co-authored-by: Mattermod <mattermod@users.noreply.github.com>

src/browser/components/MattermostView.jsx

@@ -269,8 +269,13 @@ export default class MattermostView extends React.Component {
   }
 
   goBack = () => {
-    const webview = this.webviewRef.current;
-    webview.getWebContents().goBack();
+    try {
+      const webview = this.webviewRef.current;
+      webview.getWebContents().goBack();
+    } catch (e) {
+      console.log(`Error while trying to go back in history: ${e}`);
+      this.webview.loadURL(this.props.src);
+    }
   }
 
   goForward = () => {

src/main.js

@@ -804,6 +804,16 @@ function initializeAfterAppReady() {
     });
   });
 
+  // Code for preventing user-agent checking. See: https://mattermost.atlassian.net/browse/MM-31626
+  const REMOVE_CHROME_FROM = ['https://gitlab.com/*'];
+  const nonChromeUA = session.defaultSession.getUserAgent().replace(/ Chrome\/[\d.]+/g, '');
+  session.defaultSession.webRequest.onBeforeSendHeaders({urls: REMOVE_CHROME_FROM}, (details, callback) => {
+    console.warn(`Cloud-flare url detected for ${details.url}, request will use a different User Agent`);
+    const temporaryHeaders = details.requestHeaders;
+    temporaryHeaders['User-Agent'] = nonChromeUA;
+    callback({cancel: false, requestHeaders: temporaryHeaders});
+  });
+
   ipcMain.emit('update-menu', true, config.data);
 
   ipcMain.emit('update-dict');