Fixes #378

src/main.js

@@ -219,6 +219,35 @@ function clearAppCache() {
   }
 }
 
+function getValidWindowPosition(state) {
+  // Screen cannot be required before app is ready
+  const {screen} = require('electron');
+
+  // Check if the previous position is out of the viewable area
+  // (e.g. because the screen has been plugged off)
+  const displays = screen.getAllDisplays();
+  let minX = 0;
+  let maxX = 0;
+  let minY = 0;
+  let maxY = 0;
+  for (let i = 0; i < displays.length; i++) {
+    const display = displays[i];
+    maxX = Math.max(maxX, display.bounds.x + display.bounds.width);
+    maxY = Math.max(maxY, display.bounds.y + display.bounds.height);
+    minX = Math.min(minX, display.bounds.x);
+    minY = Math.min(minY, display.bounds.y);
+  }
+
+  if (state.x > maxX || state.y > maxY || state.x < minX || state.y < minY) {
+    Reflect.deleteProperty(state, 'x');
+    Reflect.deleteProperty(state, 'y');
+    Reflect.deleteProperty(state, 'width');
+    Reflect.deleteProperty(state, 'height');
+  }
+
+  return state;
+}
+
 // Quit when all windows are closed.
 app.on('window-all-closed', () => {
   // On OS X it is common for applications and their menu bar
@@ -413,7 +442,7 @@ app.on('ready', () => {
   var boundsInfoPath = path.resolve(app.getPath('userData'), 'bounds-info.json');
   var windowOptions;
   try {
-    windowOptions = JSON.parse(fs.readFileSync(boundsInfoPath, 'utf-8'));
+    windowOptions = getValidWindowPosition(JSON.parse(fs.readFileSync(boundsInfoPath, 'utf-8')));
   } catch (e) {
     // follow Electron's defaults
     windowOptions = {};