[generator] Fix UnsupportedOSPlatform for property setters when base has getter-only

Context: dotnet/android#10510 (comment)

When a derived class has a property setter with `ApiRemovedSince`, but
the base class only has a getter (no setter), clear the setter's
`ApiRemovedSince` if the base getter is not removed. Also handle
standalone `setXxx` methods that correspond to base class properties.

Fixes `CA1416` warning for `ListView.Adapter.set` being incorrectly
marked as unsupported on `android15.0`.

Author: jonathanpeppers

tests/generator-Tests/Unit-Tests/CodeGeneratorTests.cs

@@ -1563,6 +1563,43 @@ public void UnsupportedOSPlatformIgnoresPropertyOverrides ()
 			StringAssert.DoesNotContain ("[global::System.Runtime.Versioning.UnsupportedOSPlatformAttribute (\"android30.0\")]", ifaceActual, "Should not contain UnsupportedOSPlatform on interface property override!");
 		}
 
+		[Test]
+		public void UnsupportedOSPlatformIgnoresPropertySetterOverridesWhenBaseHasGetterOnly ()
+		{
+			// Given:
+			// public class AdapterView {
+			//   public Object getAdapter () { ... }
+			// }
+			// public class ListView : AdapterView {
+			//   public Object getAdapter () { ... }           // removed-since = 15
+			//   public void setAdapter (Object value) { ... } // removed-since = 15
+			// }
+			// We should not write [UnsupportedOSPlatform] on ListView.Adapter.set because the base property (via getter) isn't "removed".
+			var xml = @$"<api>
+			  <package name='java.lang' jni-name='java/lang'>
+			    <class abstract='false' deprecated='not deprecated' final='false' name='Object' static='false' visibility='public' jni-signature='Ljava/lang/Object;' />
+			  </package>
+			  <package name='android.widget' jni-name='android/widget'>
+			    <class abstract='false' deprecated='not deprecated' extends='java.lang.Object' extends-generic-aware='java.lang.Object' final='false' name='AdapterView' static='false' visibility='public'>
+			       <method abstract='false' deprecated='not deprecated' final='false' name='getAdapter' bridge='false' native='false' return='java.lang.Object' static='false' synchronized='false' synthetic='false' visibility='public' />
+			     </class>
+			    <class abstract='false' deprecated='not deprecated' extends='android.widget.AdapterView' extends-generic-aware='android.widget.AdapterView' final='false' name='ListView' static='false' visibility='public'>
+			       <method abstract='false' deprecated='not deprecated' final='false' name='getAdapter' bridge='false' native='false' return='java.lang.Object' static='false' synchronized='false' synthetic='false' visibility='public' removed-since='15' />
+			       <method abstract='false' deprecated='not deprecated' final='false' name='setAdapter' bridge='false' native='false' return='void' static='false' synchronized='false' synthetic='false' visibility='public' removed-since='15'>
+			         <parameter name='value' type='java.lang.Object' />
+			       </method>
+			     </class>
+			  </package>
+			</api>";
+
+			var gens = ParseApiDefinition (xml);
+			var klass = gens.Single (g => g.Name == "ListView");
+			var actual = GetGeneratedTypeOutput (klass);
+
+			// Neither the getter nor the setter should have [UnsupportedOSPlatform] because the base property (getter) isn't removed
+			StringAssert.DoesNotContain ("[global::System.Runtime.Versioning.UnsupportedOSPlatformAttribute (\"android15.0\")]", actual, "Should not contain UnsupportedOSPlatform on property setter when base has getter only!");
+		}
+
 		[Test]
 		public void StringPropertyOverride ([Values ("true", "false")] string final)
 		{

tools/generator/Java.Interop.Tools.Generator.ObjectModel/GenBase.cs

@@ -366,13 +366,32 @@ public void FixupMethodOverrides (CodeGenerationOptions opt)
 							prop.Setter.ApiRemovedSince = default;
 							shouldBreak = true;
 						}
+					} else if (prop.Setter != null && prop.Setter.ApiRemovedSince > 0 && baseProp.Setter == null && baseProp.Getter != null && baseProp.Getter.ApiRemovedSince == 0) {
+						// Base has getter-only property; setter in derived should not be marked removed
+						prop.Setter.ApiRemovedSince = default;
+						shouldBreak = true;
 					}
 					if (shouldBreak) {
 						break;
 					}
 				}
 			}
 
+			// Process standalone setter methods (setXxx) that correspond to base class properties.
+			// If the base property getter isn't removed, the setter shouldn't be either.
+			foreach (var m in Methods.Where (m => !m.IsStatic && !m.IsInterfaceDefaultMethod && m.ApiRemovedSince > 0)) {
+				if (!m.JavaName.StartsWith ("set", StringComparison.Ordinal) || m.Parameters.Count != 1 || m.RetVal.JavaName != "void")
+					continue;
+				var propertyName = m.JavaName.Substring (3);
+				for (var bt = GetBaseGen (opt); bt != null; bt = bt.GetBaseGen (opt)) {
+					var baseProp = bt.Properties.FirstOrDefault (p => p.Getter?.JavaName == "get" + propertyName);
+					if (baseProp?.Getter != null && baseProp.Getter.ApiRemovedSince == 0) {
+						m.ApiRemovedSince = default;
+						break;
+					}
+				}
+			}
+
 			// Process interface inheritance for both regular and default interface methods
 			if (this is InterfaceGen currentInterface) {
 				// For interfaces, check all base interfaces (interfaces that this interface implements/extends)
@@ -419,6 +438,10 @@ public void FixupMethodOverrides (CodeGenerationOptions opt)
 								prop.Setter.ApiRemovedSince = default;
 								shouldBreak = true;
 							}
+						} else if (prop.Setter != null && prop.Setter.ApiRemovedSince > 0 && baseProp.Setter == null && baseProp.Getter != null && baseProp.Getter.ApiRemovedSince == 0) {
+							// Base has getter-only property; setter in derived should not be marked removed
+							prop.Setter.ApiRemovedSince = default;
+							shouldBreak = true;
 						}
 						if (shouldBreak) {
 							break;