Fix Android MediaPicker result recovery

src/Core/AndroidNative/maui/src/main/java/com/microsoft/maui/PlatformMauiAppCompatActivity.java

@@ -1,22 +1,45 @@
 package com.microsoft.maui;
 
-import android.content.Context;
-import android.content.res.Resources;
+import android.content.pm.ApplicationInfo;
 import android.content.res.TypedArray;
+import android.os.Bundle;
+import android.util.Log;
 
+import androidx.activity.ComponentActivity;
 import androidx.appcompat.app.AppCompatActivity;
-import android.os.Bundle;
 
+import java.lang.reflect.Field;
 
 /**
  * Class for batching native method calls within the MauiAppCompatActivity implementation
  */
 public class PlatformMauiAppCompatActivity {
+    private static final String TAG = "MauiAppCompat";
+
+    // These are AndroidX saved-instance-state keys. MAUI does not create the bundles stored under
+    // these keys; it only removes or preserves them before AppCompat restores saved state. AndroidX
+    // does not expose public constants for these values.
+    //
+    // ComponentActivity saves pending ActivityResultRegistry state here. Preserving this bundle
+    // lets AndroidX replay pending activity results after activity or process recreation.
+    private static final String ACTIVITY_RESULT_REGISTRY_KEY = "android:support:activity-result";
+
+    // AndroidX FragmentManager saved-state key. MAUI removes this when fragment restore is
+    // disabled because restoring old fragments can conflict with MAUI's own navigation/window
+    // reconstruction.
+    private static final String SUPPORT_FRAGMENTS_KEY = "android:support:fragments";
+
+    // SavedStateRegistry's top-level bundle key. Older MAUI behavior removed this whole bundle to
+    // suppress fragment restore side effects, but that also discarded ActivityResultRegistry state.
+    private static final String SAVED_STATE_REGISTRY_KEY = "androidx.lifecycle.BundlableSavedStateRegistry.key";
+
+    private static boolean activityResultRegistryKeyChecked;
+
     public static void onCreate(AppCompatActivity activity, Bundle savedInstanceState, boolean allowFragmentRestore, int splashAttr, int mauiTheme)
     {
         if (!allowFragmentRestore && savedInstanceState != null) {
-            savedInstanceState.remove("android:support:fragments");
-            savedInstanceState.remove("androidx.lifecycle.BundlableSavedStateRegistry.key");
+            warnIfActivityResultRegistryKeyChanged(activity);
+            removeFragmentRestoreState(savedInstanceState);
         }
 
         boolean mauiSplashAttrValue = false;
@@ -33,4 +56,54 @@ public static void onCreate(AppCompatActivity activity, Bundle savedInstanceStat
             activity.setTheme(mauiTheme);
         }
     }
+
+    private static void removeFragmentRestoreState(Bundle savedInstanceState)
+    {
+        // First remove the direct fragment entry that may be present in the activity state.
+        savedInstanceState.remove(SUPPORT_FRAGMENTS_KEY);
+
+        Bundle savedStateRegistry = savedInstanceState.getBundle(SAVED_STATE_REGISTRY_KEY);
+        if (savedStateRegistry != null) {
+            // The saved-state registry is a shared AndroidX container. Extract the activity-result
+            // entry before removing the container so pending activity results are not lost with the
+            // fragment-related providers.
+            Bundle activityResultRegistryState = savedStateRegistry.getBundle(ACTIVITY_RESULT_REGISTRY_KEY);
+
+            savedInstanceState.remove(SAVED_STATE_REGISTRY_KEY);
+
+            if (activityResultRegistryState != null) {
+                // Keep only the AndroidX ActivityResultRegistry state needed to replay pending
+                // results after activity/process recreation. Other saved-state providers may
+                // contain fragment state that MAUI cannot safely restore.
+                Bundle prunedSavedStateRegistry = new Bundle();
+                prunedSavedStateRegistry.putBundle(ACTIVITY_RESULT_REGISTRY_KEY, activityResultRegistryState);
+                savedInstanceState.putBundle(SAVED_STATE_REGISTRY_KEY, prunedSavedStateRegistry);
+            }
+        }
+    }
+
+    private static void warnIfActivityResultRegistryKeyChanged(AppCompatActivity activity)
+    {
+        if (activityResultRegistryKeyChecked) {
+            return;
+        }
+
+        activityResultRegistryKeyChecked = true;
+
+        if ((activity.getApplicationInfo().flags & ApplicationInfo.FLAG_DEBUGGABLE) == 0) {
+            return;
+        }
+
+        try {
+            Field field = ComponentActivity.class.getDeclaredField("ACTIVITY_RESULT_TAG");
+            field.setAccessible(true);
+            Object value = field.get(null);
+
+            if (!ACTIVITY_RESULT_REGISTRY_KEY.equals(value)) {
+                Log.w(TAG, "AndroidX ActivityResultRegistry saved-state key changed; MediaPicker recovery may be affected.");
+            }
+        } catch (Throwable ex) {
+            Log.w(TAG, "Unable to verify AndroidX ActivityResultRegistry saved-state key.", ex);
+        }
+    }
 }

src/Core/tests/DeviceTests/Platform/AndroidXActivityResultRegistryTests.Android.cs

@@ -0,0 +1,24 @@
+using AndroidX.Activity;
+using Xunit;
+using JavaClass = Java.Lang.Class;
+
+namespace Microsoft.Maui.DeviceTests
+{
+	[Category(TestCategory.Application)]
+	public class AndroidXActivityResultRegistryTests
+	{
+		const string ExpectedActivityResultRegistryKey = "android:support:activity-result";
+
+		[Fact]
+		public void ComponentActivity_ActivityResultSavedStateKey_MatchesMauiRecoveryKey()
+		{
+			using var componentActivityClass = JavaClass.FromType(typeof(ComponentActivity));
+			using var activityResultTagField = componentActivityClass.GetDeclaredField("ACTIVITY_RESULT_TAG");
+			activityResultTagField.Accessible = true;
+
+			var activityResultTag = activityResultTagField.Get(null)?.ToString();
+
+			Assert.Equal(ExpectedActivityResultRegistryKey, activityResultTag);
+		}
+	}
+}

src/Essentials/src/FileSystem/FileSystemUtils.android.cs

@@ -1,6 +1,7 @@
 using System;
 using System.Diagnostics;
 using System.IO;
+using System.Threading.Tasks;
 using Android.App;
 using Android.Provider;
 using Android.Webkit;
@@ -71,6 +72,17 @@ public static string EnsurePhysicalPath(AndroidUri uri, bool requireExtendedAcce
 			throw new FileNotFoundException($"Unable to resolve absolute path or retrieve contents of URI '{uri}'.");
 		}
 
+		public static Task<string> EnsurePhysicalPathAsync(AndroidUri uri, bool requireExtendedAccess = true)
+		{
+			// file:// URIs do not need provider queries or stream copies.
+			if (string.Equals(uri.Scheme, UriSchemeFile, StringComparison.OrdinalIgnoreCase))
+			{
+				return Task.FromResult(uri.Path);
+			}
+
+			return Task.Run(() => EnsurePhysicalPath(uri, requireExtendedAccess));
+		}
+
 		static string ResolvePhysicalPath(AndroidUri uri, bool requireExtendedAccess = true)
 		{
 			if (uri.Scheme.Equals(UriSchemeFile, StringComparison.OrdinalIgnoreCase))