autofill: avoid crash when looking up a null key.

closes https://github.com/PhilippC/keepass2android/issues/2362

src/Kp2aAutofillParser/AutofillParser.cs

@@ -445,6 +445,9 @@ namespace Kp2aAutofillParser
 
         public static string ToCanonicalHint(string hint)
         {
+            //avoid crash when looking up a null key
+            if (hint == null)
+                return "";
             string canonicalHint;
             if (!hintToCanonicalReplacement.TryGetValue(hint, out canonicalHint))
                 canonicalHint = hint;
@@ -841,6 +844,7 @@ namespace Kp2aAutofillParser
                         continue;
                     if (viewHints.Where(h => h != null).Select(AutofillHintsHelper.ToCanonicalHint).Intersect(_autofillHintsForLogin).Any())
                     {
+
                         AddFieldToHintMap(viewNode, viewHints.Where(h => h != null).Select(AutofillHintsHelper.ToCanonicalHint).ToHashSet().ToArray());
                     }
 

src/keepass2android-app/EntryEditActivity.cs

@@ -37,7 +37,6 @@ using System.Net;
 using System.Text;
 using Android.Content.Res;
 using Android.Database;
-using Android.Gms.Common;
 using Android.Gms.Tasks;
 using Android.Graphics;
 using Android.Graphics.Drawables;
@@ -1156,12 +1155,6 @@ namespace keepass2android
 
             dlgView.FindViewById<Button>(Resource.Id.totp_scan).Click += async (object o, EventArgs args) =>
             {
-                if (GoogleApiAvailability.Instance.IsGooglePlayServicesAvailable(this) != ConnectionResult.Success)
-                {
-                    Toast.MakeText(this, Resource.String.qr_scanning_error_no_google_play_services, ToastLength.Long);
-                    return;
-                }
-
 				GmsBarcodeScannerOptions options = new GmsBarcodeScannerOptions.Builder()
                     .SetBarcodeFormats(Barcode.FormatQrCode)
                     .Build();

src/keepass2android-app/NullActivity.cs

@@ -0,0 +1,24 @@
+using Android.Content.PM;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace keepass2android
+{
+    [Activity(Label = AppNames.AppName,
+        MainLauncher = false,
+        Theme = "@style/Kp2aTheme_BlueNoActionBar",
+        Exported = true)] 
+    ///For autofill, we sometimes need to pass an intent to an inline presentation which never gets fired. We use this as a dummy activity.
+    public class NullActivity: Activity
+    {
+        protected override void OnCreate(Bundle savedInstanceState)
+        {
+            Kp2aLog.Log("NullActivity.OnCreate - this is unexpected.");
+            base.OnCreate(savedInstanceState);
+            Finish();
+        }
+    }
+}

src/keepass2android-app/Resources/values/strings.xml

@@ -548,7 +548,6 @@
   <string name="filestoragename_dropboxKP2A">Dropbox (KP2A folder)</string>
   <string name="filestoragehelp_dropboxKP2A">If you do not want to give KP2A access to your full Dropbox, you may select this option. It will request only access to the folder Apps/Keepass2Android. This is especially suited when creating a new database. If you already have a database, select this option to create the folder, then place your file inside the folder (from your PC) and then select this option again for opening the file.</string>
   <string name="filestoragename_gdrive">Google Drive</string>
-  <string name="filestoragehelp_gdrive">Please note: Google is restricting access to Google Drive from apps for more and more users. If the built-in Google Drive implementation does not work, please use System file picker instead and select Google Drive there!</string>
   <string name="filestoragename_gdriveKP2A">Google Drive (KP2A files)</string>
   <string name="filestoragehelp_gdriveKP2A">If you do not want to give KP2A access to your full Google Drive, you may select this option. Note that you need to create a database file first, existing files are not visible to the app. Either choose this option from the Create database screen or, if you already opened a database, by exporting the database choosing this option.</string>
   <string name="filestoragename_pcloud">PCloud (KP2A folder)</string>
@@ -1246,7 +1245,6 @@
   <string name="AutofillWarning_trustAsBrowser">Accept always in "%1$s"</string>
   <string name="kp2a_switch_on_sendgodone">Switch back when done</string>
   <string name="kp2a_switch_on_sendgodone_summary">Switch back when pressing send/go/done</string>
-  <string name="qr_scanning_error_no_google_play_services">QR code scanning requires Google Play Services. Please install or update Google Play Services on your device.</string>
 <string name="english_ime_settings">Android keyboard settings</string>
     
     </resources>

src/keepass2android-app/services/AutofillBase/AutofillHelper.cs

@@ -30,10 +30,9 @@ namespace keepass2android.services.AutofillBase
             {
                 return null;
             }
-            //make sure we have a pendingIntent always not null
-            pendingIntent ??= PendingIntent.GetService(context, 0, new Intent(),
-                Util.AddMutabilityFlag(PendingIntentFlags.OneShot | PendingIntentFlags.UpdateCurrent, PendingIntentFlags.Mutable));
-            
+            // If the pending intent is null, we need to create a dummy one to avoid a crash
+            pendingIntent ??= PendingIntent.GetActivity(context, 0, new Intent(context, typeof(NullActivity)), PendingIntentFlags.OneShot | PendingIntentFlags.UpdateCurrent | PendingIntentFlags.Immutable);
+
             var slice = CreateInlinePresentationSlice(
                 inlinePresentationSpec,
                 text,

src/keepass2android-app/services/AutofillBase/AutofillServiceBase.cs

@@ -405,7 +405,7 @@ namespace keepass2android.services.AutofillBase
             var datasetBuilder = new Dataset.Builder(presentation);
             datasetBuilder.SetAuthentication(pendingIntent?.IntentSender);
 
-            AutofillHelper.AddInlinePresentation(this, inlinePresentationSpec, text, datasetBuilder, Resource.Drawable.baseline_close_24, null);
+            AutofillHelper.AddInlinePresentation(this, inlinePresentationSpec, text, datasetBuilder, Resource.Drawable.baseline_close_24, pendingIntent);
 
             foreach (var autofillId in autofillIds)
             {