fix(browser): stop close() from re-opening the last URL on Android

browser/android/src/main/java/com/capacitorjs/plugins/browser/BrowserControllerActivity.java

@@ -19,15 +19,26 @@ public class BrowserControllerActivity extends ComponentActivity {
     protected void onCreate(@Nullable Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
 
+        // close() starts a new instance when the previous one was already cleared off the task
+        // (e.g. by a deep link into a singleTask activity) but not destroyed yet. There is nothing
+        // to close then, and the last open() must not run again.
+        if (getIntent().hasExtra("close")) {
+            finish();
+            return;
+        }
+
         customTabLauncher = registerForActivityResult(new ActivityResultContracts.StartActivityForResult(), (result) -> {
             if (implementation != null) {
                 implementation.notifyBrowserFinished();
             }
             finish();
         });
 
-        if (BrowserPlugin.browserControllerListener != null) {
-            BrowserPlugin.browserControllerListener.onControllerReady(this);
+        // Each open() is served once, by the controller it started.
+        BrowserControllerListener listener = BrowserPlugin.browserControllerListener;
+        BrowserPlugin.browserControllerListener = null;
+        if (listener != null) {
+            listener.onControllerReady(this);
         }
     }
 
@@ -64,6 +75,6 @@ public void open(Browser implementation, Uri url, Integer toolbarColor) {
     protected void onDestroy() {
         super.onDestroy();
         implementation = null;
-        BrowserPlugin.setBrowserControllerListener(null);
+        BrowserPlugin.onControllerDestroyed(this);
     }
 }

browser/android/src/main/java/com/capacitorjs/plugins/browser/BrowserPlugin.java

@@ -15,8 +15,9 @@ public class BrowserPlugin extends Plugin {
 
     private Browser implementation;
 
-    public static BrowserControllerListener browserControllerListener;
-    private static BrowserControllerActivity browserControllerActivityInstance;
+    // Written on the plugin thread, read on the main thread.
+    public static volatile BrowserControllerListener browserControllerListener;
+    private static volatile BrowserControllerActivity browserControllerActivityInstance;
 
     public static void setBrowserControllerListener(BrowserControllerListener listener) {
         browserControllerListener = listener;
@@ -25,6 +26,16 @@ public static void setBrowserControllerListener(BrowserControllerListener listen
         }
     }
 
+    /**
+     * Called by each controller as it is destroyed. It forgets that controller only: the listener
+     * may already belong to a newer open() whose controller has not been created yet.
+     */
+    static void onControllerDestroyed(BrowserControllerActivity activity) {
+        if (browserControllerActivityInstance == activity) {
+            browserControllerActivityInstance = null;
+        }
+    }
+
     public void load() {
         implementation = new Browser(getContext());
         implementation.setBrowserEventListener(this::onBrowserEvent);
@@ -61,11 +72,7 @@ public void open(PluginCall call) {
 
         // open the browser and finish
 
-        Intent intent = new Intent(getContext(), BrowserControllerActivity.class);
-        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
-        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-        getContext().startActivity(intent);
-
+        // Set the listener before starting the activity, so its onCreate can't run first and miss it.
         Integer finalToolbarColor = toolbarColor;
         setBrowserControllerListener((activity) -> {
             try {
@@ -77,6 +84,11 @@ public void open(PluginCall call) {
                 call.reject("Unable to display URL");
             }
         });
+
+        Intent intent = new Intent(getContext(), BrowserControllerActivity.class);
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
+        intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
+        getContext().startActivity(intent);
     }
 
     @PluginMethod