attempt to fix stale tabs

App/Browser View/BrowserViewController.swift

@@ -594,6 +594,19 @@ class BrowserViewController: UIViewController
         
         // Blur url bar, if applicable
         toolbarController.urlBar.textField.resignFirstResponder()
+
+        // If this tab's web content process was jettisoned while in background,
+        // its current page may appear blank and url be nil. Proactively reload
+        // when the tab becomes active again to restore state.
+        if tab.contentProcessTerminated {
+            if webView.url != nil || tab.url != nil {
+                webView.reload()
+            } else if let home = tab.homeURL {
+                tab.beginLoadingURL(home)
+            } else {
+                webView.reload()
+            }
+        }
     }
     
     override func target(forAction action: Selector, withSender sender: Any?) -> Any? {
@@ -618,6 +631,18 @@ class BrowserViewController: UIViewController
     override func viewWillAppear(_ animated: Bool) {
         super.viewWillAppear(animated)
         becomeFirstResponder()
+
+        // If the app resumed and the current tab's web content process was
+        // terminated while in background, ensure we restore it now.
+        if currentTab.contentProcessTerminated {
+            if webView.url != nil || currentTab.url != nil {
+                webView.reload()
+            } else if let home = currentTab.homeURL {
+                currentTab.beginLoadingURL(home)
+            } else {
+                webView.reload()
+            }
+        }
     }
         
     internal func updateScriptBlockerButton() {