#590 Update methods are not supported for "method-and-conversion" methods (can currently cause NullPointerExceptions)

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

@@ -31,9 +31,9 @@ import org.mapstruct.ap.internal.conversion.ConversionProvider;
 import org.mapstruct.ap.internal.conversion.Conversions;
 import org.mapstruct.ap.internal.model.AssignmentFactory;
 import org.mapstruct.ap.internal.model.MapperReference;
+import org.mapstruct.ap.internal.model.MappingBuilderContext.MappingResolver;
 import org.mapstruct.ap.internal.model.MethodReference;
 import org.mapstruct.ap.internal.model.VirtualMappingMethod;
-import org.mapstruct.ap.internal.model.MappingBuilderContext.MappingResolver;
 import org.mapstruct.ap.internal.model.assignment.Assignment;
 import org.mapstruct.ap.internal.model.common.ConversionContext;
 import org.mapstruct.ap.internal.model.common.DefaultConversionContext;
@@ -391,6 +391,10 @@ public class MappingResolverImpl implements MappingResolver {
 
             // search the other way around
             for ( Method methodXCandidate : methodXCandidates ) {
+                if ( methodXCandidate.getMappingTargetParameter() != null ) {
+                    continue;
+                }
+
                 Assignment methodRefX = resolveViaMethod(
                     sourceType,
                     methodXCandidate.getReturnType(),

processor/src/test/java/org/mapstruct/ap/test/bugs/_590/Issue590Test.java

@@ -0,0 +1,47 @@
+/**
+ *  Copyright 2012-2015 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.mapstruct.ap.test.bugs._590;
+
+import javax.tools.Diagnostic.Kind;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.compilation.annotation.CompilationResult;
+import org.mapstruct.ap.testutil.compilation.annotation.Diagnostic;
+import org.mapstruct.ap.testutil.compilation.annotation.ExpectedCompilationOutcome;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+/**
+ * @author Andreas Gudian
+ */
+@RunWith(AnnotationProcessorTestRunner.class)
+@WithClasses(SourceTargetMapper.class)
+public class Issue590Test {
+
+    @Test
+    @ExpectedCompilationOutcome(value = CompilationResult.FAILED,
+        diagnostics = { @Diagnostic(type = SourceTargetMapper.class,
+            kind = Kind.ERROR,
+            line = 34,
+            messageRegExp = "Can't map property \"[^ ]+ [^\"]+\" to \"[^ ]+ [^\"]+\"") })
+    public void showsCantMapPropertyError() {
+
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_590/SourceTargetMapper.java

@@ -0,0 +1,63 @@
+/**
+ *  Copyright 2012-2015 Gunnar Morling (http://www.gunnarmorling.de/)
+ *  and/or other contributors as indicated by the @authors tag. See the
+ *  copyright.txt file in the distribution for a full listing of all
+ *  contributors.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+package org.mapstruct.ap.test.bugs._590;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.MappingTarget;
+import org.mapstruct.ReportingPolicy;
+import org.mapstruct.TargetType;
+import org.mapstruct.factory.Mappers;
+
+/**
+ * @author Andreas Gudian
+ */
+@Mapper(unmappedTargetPolicy = ReportingPolicy.WARN)
+public abstract class SourceTargetMapper {
+    public static final SourceTargetMapper INSTANCE = Mappers.getMapper( SourceTargetMapper.class );
+
+    public abstract void sourceToTarget(@MappingTarget Target target, Source source);
+
+    public <T extends Target> T unused(String string, @TargetType Class<T> clazz) {
+        throw new RuntimeException( "should never be called" );
+    }
+
+    public static class Source {
+        private String prop;
+
+        public String getProp() {
+            return prop;
+        }
+
+        public void setProp(String prop) {
+            this.prop = prop;
+        }
+    }
+
+    public static class Target {
+        private StringBuilder prop;
+
+        public StringBuilder getProp() {
+            return prop;
+        }
+
+        public void setProp(StringBuilder prop) {
+            this.prop = prop;
+        }
+    }
+}