#3057: limit do not allow self to subclassmappings. (#3063)

* #3057: limit do not allow self to subclassmappings.
* #3057: determine method candidates after all other fields are set in the constructor.

Co-authored-by: Ben Zegveld <Ben.Zegveld@gmail.com>
Co-authored-by: Filip Hrisafov <filip.hrisafov@gmail.com>

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

@@ -399,15 +399,13 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                 "SubclassMapping for " + sourceType.getFullyQualifiedName() );
             SelectionCriteria criteria =
                 SelectionCriteria
-                                 .forMappingMethods(
+                                 .forSubclassMappingMethods(
                                      new SelectionParameters(
                                          Collections.emptyList(),
                                          Collections.emptyList(),
                                          subclassMappingOptions.getTarget(),
                                          ctx.getTypeUtils() ).withSourceRHS( rightHandSide ),
-                                     subclassMappingOptions.getMappingControl( ctx.getElementUtils() ),
+                                     subclassMappingOptions.getMappingControl( ctx.getElementUtils() ) );
-                                     null,
-                                     false );
             Assignment assignment = ctx
                                    .getMappingResolver()
                                    .getTargetAssignment(

processor/src/main/java/org/mapstruct/ap/internal/model/source/selector/SelectionCriteria.java

@@ -149,6 +149,10 @@ public class SelectionCriteria {
         return allow2Steps;
     }
 
+    public boolean isSelfAllowed() {
+        return type != Type.SELF_NOT_ALLOWED;
+    }
+
     public static SelectionCriteria forMappingMethods(SelectionParameters selectionParameters,
                                                       MappingControl mappingControl,
                                                       String targetPropertyName, boolean preferUpdateMapping) {
@@ -173,10 +177,16 @@ public class SelectionCriteria {
         return new SelectionCriteria( selectionParameters, null, null, Type.PRESENCE_CHECK );
     }
 
+    public static SelectionCriteria forSubclassMappingMethods(SelectionParameters selectionParameters,
+        MappingControl mappingControl) {
+        return new SelectionCriteria( selectionParameters, mappingControl, null, Type.SELF_NOT_ALLOWED );
+    }
+
     public enum Type {
         PREFER_UPDATE_MAPPING,
         OBJECT_FACTORY,
         LIFECYCLE_CALLBACK,
         PRESENCE_CHECK,
+        SELF_NOT_ALLOWED,
     }
 }

processor/src/main/java/org/mapstruct/ap/internal/processor/creation/MappingResolverImpl.java

@@ -196,7 +196,6 @@ public class MappingResolverImpl implements MappingResolver {
 
             this.mappingMethod = mappingMethod;
             this.description = description;
-            this.methods = filterPossibleCandidateMethods( sourceModel, mappingMethod );
             this.formattingParameters =
                 formattingParameters == null ? FormattingParameters.EMPTY : formattingParameters;
             this.sourceRHS = sourceRHS;
@@ -207,13 +206,14 @@ public class MappingResolverImpl implements MappingResolver {
             this.builtIns = builtIns;
             this.messager = messager;
             this.reportingLimitAmbiguous = verboseLogging ? Integer.MAX_VALUE : LIMIT_REPORTING_AMBIGUOUS;
+            this.methods = filterPossibleCandidateMethods( sourceModel, mappingMethod );
         }
         // CHECKSTYLE:ON
 
         private <T extends Method> List<T> filterPossibleCandidateMethods(List<T> candidateMethods, T mappingMethod) {
             List<T> result = new ArrayList<>( candidateMethods.size() );
             for ( T candidate : candidateMethods ) {
-                if ( isCandidateForMapping( candidate ) && !candidate.equals( mappingMethod )) {
+                if ( isCandidateForMapping( candidate ) && isNotSelfOrSelfAllowed( mappingMethod, candidate )) {
                     result.add( candidate );
                 }
             }
@@ -221,6 +221,10 @@ public class MappingResolverImpl implements MappingResolver {
             return result;
         }
 
+        private <T extends Method> boolean isNotSelfOrSelfAllowed(T mappingMethod, T candidate) {
+            return selectionCriteria == null || selectionCriteria.isSelfAllowed() || !candidate.equals( mappingMethod );
+        }
+
         private Assignment getTargetAssignment(Type sourceType, Type targetType) {
 
             Assignment assignment;

processor/src/test/java/org/mapstruct/ap/test/bugs/_3057/Issue3057Mapper.java

@@ -0,0 +1,55 @@
+/*
+ * 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._3057;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Ben Zegveld
+ */
+@Mapper
+public interface Issue3057Mapper {
+
+    Issue3057Mapper INSTANCE = Mappers.getMapper( Issue3057Mapper.class );
+
+    class Source {
+        private Source self;
+
+        public Source getSelf() {
+            return self;
+        }
+
+        public void setSelf(Source self) {
+            this.self = self;
+        }
+    }
+
+    class Target {
+        private Target self;
+        private String value;
+
+        public Target getSelf() {
+            return self;
+        }
+
+        public void setSelf(Target self) {
+            this.self = self;
+        }
+
+        public String getValue() {
+            return value;
+        }
+
+        public void setValue(String value) {
+            this.value = value;
+        }
+    }
+
+    @Mapping( target = "value", constant = "constantValue" )
+    Target map(Source source);
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_3057/Issue3057MapperTest.java

@@ -0,0 +1,34 @@
+/*
+ * 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._3057;
+
+import org.mapstruct.ap.test.bugs._3057.Issue3057Mapper.Source;
+import org.mapstruct.ap.test.bugs._3057.Issue3057Mapper.Target;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.ProcessorTest;
+import org.mapstruct.ap.testutil.WithClasses;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * @author Ben Zegveld
+ */
+@WithClasses(Issue3057Mapper.class)
+@IssueKey("3057")
+class Issue3057MapperTest {
+
+    @ProcessorTest
+    void mapsSelf() {
+        Source sourceOuter = new Issue3057Mapper.Source();
+        Source sourceInner = new Issue3057Mapper.Source();
+        sourceOuter.setSelf( sourceInner );
+
+        Target targetOuter = Issue3057Mapper.INSTANCE.map( sourceOuter );
+
+        assertThat( targetOuter.getValue() ).isEqualTo( "constantValue" );
+        assertThat( targetOuter.getSelf().getValue() ).isEqualTo( "constantValue" );
+    }
+}