Fix NullReferenceException and crash in ManifestExtensions (#182)

* Fix NullReferenceException and crash in ManifestExtensions

- GetWKAppBundleIdentifier: handle null from GetNSExtensionAttributes.
- SetWKAppBundleIdentifier: auto-create NSExtension/NSExtensionAttributes
  structure when setting a non-empty value (avoid silent no-op).
- ParseDeviceFamilyFromNumber → TryParseDeviceFamilyFromNumber: unknown
  device family numbers are now logged and skipped (not coerced to IPhone),
  consistent with how the string parser already handles unknown values.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Fix misleading log message in TryParseDeviceFamilyFromNumber

Changed 'Skipped unknown device family' to 'Ignoring unrecognized device family number'
to make it clear the value is not mapped to any family and is simply discarded.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: rmarinho

Xamarin.MacDev/ManifestExtensions.cs

@@ -218,21 +218,28 @@ public static IPhoneDeviceType GetUIDeviceFamily (this PDictionary dict)
 			return GetUIDeviceFamily (dict, ManifestKeys.UIDeviceFamily);
 		}
 
-		static AppleDeviceFamily ParseDeviceFamilyFromNumber (PNumber number)
+		static bool TryParseDeviceFamilyFromNumber (PNumber number, out AppleDeviceFamily family)
 		{
 			switch (number.Value) {
 			case 1:
-				return AppleDeviceFamily.IPhone;
+				family = AppleDeviceFamily.IPhone;
+				return true;
 			case 2:
-				return AppleDeviceFamily.IPad;
+				family = AppleDeviceFamily.IPad;
+				return true;
 			case 3:
-				return AppleDeviceFamily.TV;
+				family = AppleDeviceFamily.TV;
+				return true;
 			case 4:
-				return AppleDeviceFamily.Watch;
+				family = AppleDeviceFamily.Watch;
+				return true;
 			case 6:
-				return AppleDeviceFamily.MacCatalystOptimizedForMac;
+				family = AppleDeviceFamily.MacCatalystOptimizedForMac;
+				return true;
 			default:
-				throw new ArgumentOutOfRangeException (string.Format ("Unknown device family: {0}", number.Value));
+				LoggingService.LogWarning ($"Ignoring unrecognized device family number: {number.Value}");
+				family = default;
+				return false;
 			}
 		}
 
@@ -278,11 +285,12 @@ public static IPhoneDeviceType GetUIDeviceFamily (this PDictionary dict, string
 						val |= ParseDeviceTypeFromString (p);
 
 					var number = element as PNumber;
-					if (number != null)
-						val |= ParseDeviceFamilyFromNumber (number).ToDeviceType ();
+					if (number != null && TryParseDeviceFamilyFromNumber (number, out var family))
+						val |= family.ToDeviceType ();
 				}
 			} else if (value is PNumber) {
-				val |= ParseDeviceFamilyFromNumber ((PNumber) value).ToDeviceType ();
+				if (TryParseDeviceFamilyFromNumber ((PNumber) value, out var family))
+					val |= family.ToDeviceType ();
 			} else if (value is PString) {
 				val |= ParseDeviceTypeFromString ((PString) value);
 			}
@@ -496,6 +504,23 @@ static PDictionary GetNSExtensionAttributes (this PDictionary dict)
 			return extAtt;
 		}
 
+		static PDictionary GetOrCreateNSExtensionAttributes (this PDictionary dict)
+		{
+			var ext = dict.Get<PDictionary> ("NSExtension");
+			if (ext == null) {
+				ext = new PDictionary ();
+				dict ["NSExtension"] = ext;
+			}
+
+			var extAtt = ext.Get<PDictionary> ("NSExtensionAttributes");
+			if (extAtt == null) {
+				extAtt = new PDictionary ();
+				ext ["NSExtensionAttributes"] = extAtt;
+			}
+
+			return extAtt;
+		}
+
 		#endregion
 
 		#region Watch App Manifest Keys
@@ -513,19 +538,23 @@ public static void SetWKWatchKitApp (this PDictionary dict, bool value)
 		public static string GetWKAppBundleIdentifier (this PDictionary dict)
 		{
 			var extAtt = GetNSExtensionAttributes (dict);
+			if (extAtt == null)
+				return null;
 
 			var str = extAtt.Get<PString> (ManifestKeys.WKAppBundleIdentifier);
 			return str == null ? null : str.Value;
 		}
 
 		public static void SetWKAppBundleIdentifier (this PDictionary dict, string value)
 		{
-			var extAtt = GetNSExtensionAttributes (dict);
-
-			if (string.IsNullOrEmpty (value))
-				extAtt.Remove (ManifestKeys.WKAppBundleIdentifier);
-			else
+			if (string.IsNullOrEmpty (value)) {
+				var extAtt = GetNSExtensionAttributes (dict);
+				if (extAtt != null)
+					extAtt.Remove (ManifestKeys.WKAppBundleIdentifier);
+			} else {
+				var extAtt = GetOrCreateNSExtensionAttributes (dict);
 				extAtt [ManifestKeys.WKAppBundleIdentifier] = value;
+			}
 		}
 
 		public static string GetWKCompanionAppBundleIdentifier (this PDictionary dict)

tests/ManifestExtensionsTests.cs

@@ -0,0 +1,100 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+#nullable enable
+
+using NUnit.Framework;
+using Xamarin.MacDev;
+
+namespace tests {
+
+	[TestFixture]
+	public class ManifestExtensionsTests {
+
+		[Test]
+		public void GetWKAppBundleIdentifier_ReturnsNull_WhenNSExtensionMissing ()
+		{
+			var dict = new PDictionary ();
+			var result = dict.GetWKAppBundleIdentifier ();
+			Assert.That (result, Is.Null);
+		}
+
+		[Test]
+		public void GetWKAppBundleIdentifier_ReturnsNull_WhenNSExtensionAttributesMissing ()
+		{
+			var dict = new PDictionary ();
+			dict.Add ("NSExtension", new PDictionary ());
+			var result = dict.GetWKAppBundleIdentifier ();
+			Assert.That (result, Is.Null);
+		}
+
+		[Test]
+		public void GetWKAppBundleIdentifier_ReturnsValue_WhenPresent ()
+		{
+			var dict = new PDictionary ();
+			var ext = new PDictionary ();
+			var extAttr = new PDictionary ();
+			extAttr.Add ("WKAppBundleIdentifier", new PString ("com.test.watchapp"));
+			ext.Add ("NSExtensionAttributes", extAttr);
+			dict.Add ("NSExtension", ext);
+
+			var result = dict.GetWKAppBundleIdentifier ();
+			Assert.That (result, Is.EqualTo ("com.test.watchapp"));
+		}
+
+		[Test]
+		public void SetWKAppBundleIdentifier_CreatesStructure_WhenNSExtensionMissing ()
+		{
+			var dict = new PDictionary ();
+			dict.SetWKAppBundleIdentifier ("com.test.app");
+			Assert.That (dict.GetWKAppBundleIdentifier (), Is.EqualTo ("com.test.app"));
+		}
+
+		[Test]
+		public void SetWKAppBundleIdentifier_RemoveIsNoOp_WhenNSExtensionMissing ()
+		{
+			var dict = new PDictionary ();
+			Assert.DoesNotThrow (() => dict.SetWKAppBundleIdentifier (""));
+		}
+
+		[Test]
+		public void GetUIDeviceFamily_SkipsUnknownDeviceFamilyNumber ()
+		{
+			var dict = new PDictionary ();
+			var arr = new PArray ();
+			arr.Add (new PNumber (99));
+			dict.Add ("UIDeviceFamily", arr);
+
+			var result = dict.GetUIDeviceFamily ("UIDeviceFamily");
+			Assert.That (result, Is.EqualTo (IPhoneDeviceType.NotSet));
+		}
+
+		[Test]
+		public void GetUIDeviceFamily_MixedKnownAndUnknown_SkipsUnknown ()
+		{
+			var dict = new PDictionary ();
+			var arr = new PArray ();
+			arr.Add (new PNumber (2)); // IPad
+			arr.Add (new PNumber (99)); // unknown — should be skipped
+			dict.Add ("UIDeviceFamily", arr);
+
+			var result = dict.GetUIDeviceFamily ("UIDeviceFamily");
+			Assert.That (result.HasFlag (IPhoneDeviceType.IPad), Is.True);
+			Assert.That (result.HasFlag (IPhoneDeviceType.IPhone), Is.False);
+		}
+
+		[Test]
+		public void GetUIDeviceFamily_ParsesKnownDeviceFamilies ()
+		{
+			var dict = new PDictionary ();
+			var arr = new PArray ();
+			arr.Add (new PNumber (1));
+			arr.Add (new PNumber (2));
+			dict.Add ("UIDeviceFamily", arr);
+
+			var result = dict.GetUIDeviceFamily ("UIDeviceFamily");
+			Assert.That (result.HasFlag (IPhoneDeviceType.IPhone), Is.True);
+			Assert.That (result.HasFlag (IPhoneDeviceType.IPad), Is.True);
+		}
+	}
+}