#2133 @BeanMapping#resultType should not be applied to forged methods (#2134)

* #2133 reproducer

* #2133 solution

processor/src/main/java/org/mapstruct/ap/internal/model/BeanMappingMethod.java

@@ -472,7 +472,10 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
         }
 
         private Type getReturnTypeToConstructFromSelectionParameters(SelectionParameters selectionParams) {
-            if ( selectionParams != null && selectionParams.getResultType() != null ) {
+            // resultType only applies to method that actually has @BeanMapping annotation, never to forged methods
+            if ( !( method instanceof ForgedMethod )
+                && selectionParams != null
+                && selectionParams.getResultType() != null ) {
                 return ctx.getTypeFactory().getType( selectionParams.getResultType() );
             }
             return null;

processor/src/test/java/org/mapstruct/ap/test/bugs/_2133/Issue2133Mapper.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._2133;
+
+import org.mapstruct.BeanMapping;
+import org.mapstruct.Mapper;
+import org.mapstruct.factory.Mappers;
+
+@Mapper
+public interface Issue2133Mapper {
+
+    Issue2133Mapper INSTANCE = Mappers.getMapper( Issue2133Mapper.class );
+
+    @BeanMapping(resultType = Target.class)
+    AbstractTarget map(Source source);
+
+    class Source {
+
+        private EmbeddedDto embedded;
+
+        public EmbeddedDto getEmbedded() {
+            return embedded;
+        }
+
+        public void setEmbedded(EmbeddedDto embedded) {
+            this.embedded = embedded;
+        }
+    }
+
+    class Target extends AbstractTarget {
+    }
+
+    abstract class AbstractTarget {
+
+        private EmbeddedEntity embedded;
+
+        public EmbeddedEntity getEmbedded() {
+            return embedded;
+        }
+
+        public void setEmbedded(EmbeddedEntity embedded) {
+            this.embedded = embedded;
+        }
+    }
+
+    class EmbeddedDto {
+
+        private String s1;
+
+        public String getS1() {
+            return s1;
+        }
+
+        public void setS1(String s1) {
+            this.s1 = s1;
+        }
+    }
+
+    class EmbeddedEntity {
+
+        private String s1;
+
+        public String getS1() {
+            return s1;
+        }
+
+        public void setS1(String s1) {
+            this.s1 = s1;
+        }
+
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2133/Issue2133Test.java

@@ -0,0 +1,23 @@
+/*
+ * Copyright MapStruct Authors.
+ *
+ * Licensed under the Apache License version 2.0, available at http://www.apache.org/licenses/LICENSE-2.0
+ */
+package org.mapstruct.ap.test.bugs._2133;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+@IssueKey("2133")
+@WithClasses( Issue2133Mapper.class )
+@RunWith(AnnotationProcessorTestRunner.class)
+public class Issue2133Test {
+
+    @Test
+    public void shouldCompile() {
+    }
+
+}