#1111 local variabele should not clash with loop variable

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

@@ -22,6 +22,7 @@ import static org.mapstruct.ap.internal.util.Collections.first;
 
 import java.text.MessageFormat;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
 import java.util.HashMap;
@@ -211,6 +212,7 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
 
             return new BeanMappingMethod(
                 method,
+                existingVariableNames,
                 propertyMappings,
                 factoryMethod,
                 mapNullToDefault,
@@ -724,6 +726,7 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
     }
 
     private BeanMappingMethod(Method method,
+                              Collection<String> existingVariableNames,
                               List<PropertyMapping> propertyMappings,
                               MethodReference factoryMethod,
                               boolean mapNullToDefault,
@@ -732,6 +735,7 @@ public class BeanMappingMethod extends NormalTypeMappingMethod {
                               List<LifecycleCallbackMethodReference> afterMappingReferences) {
         super(
             method,
+            existingVariableNames,
             factoryMethod,
             mapNullToDefault,
             beforeMappingReferences,

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

@@ -18,6 +18,7 @@
  */
 package org.mapstruct.ap.internal.model;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Set;
 
@@ -39,16 +40,21 @@ public abstract class ContainerMappingMethod extends NormalTypeMappingMethod {
     private final Assignment elementAssignment;
     private final String loopVariableName;
     private final SelectionParameters selectionParameters;
+    private final String index1Name;
+    private final String index2Name;
 
-    ContainerMappingMethod(Method method, Assignment parameterAssignment, MethodReference factoryMethod,
+    ContainerMappingMethod(Method method, Collection<String> existingVariables, Assignment parameterAssignment,
-        boolean mapNullToDefault, String loopVariableName,
+        MethodReference factoryMethod, boolean mapNullToDefault, String loopVariableName,
         List<LifecycleCallbackMethodReference> beforeMappingReferences,
         List<LifecycleCallbackMethodReference> afterMappingReferences,
         SelectionParameters selectionParameters) {
-        super( method, factoryMethod, mapNullToDefault, beforeMappingReferences, afterMappingReferences );
+        super( method, existingVariables, factoryMethod, mapNullToDefault, beforeMappingReferences,
+            afterMappingReferences );
         this.elementAssignment = parameterAssignment;
         this.loopVariableName = loopVariableName;
         this.selectionParameters = selectionParameters;
+        this.index1Name = Strings.getSaveVariableName( "i", existingVariables );
+        this.index2Name = Strings.getSaveVariableName( "j", existingVariables );
     }
 
     public Parameter getSourceParameter() {
@@ -81,11 +87,11 @@ public abstract class ContainerMappingMethod extends NormalTypeMappingMethod {
     public abstract Type getResultElementType();
 
     public String getIndex1Name() {
-        return Strings.getSaveVariableName( "i", loopVariableName, getSourceParameter().getName(), getResultName() );
+        return index1Name;
     }
 
     public String getIndex2Name() {
-        return Strings.getSaveVariableName( "j", loopVariableName, getSourceParameter().getName(), getResultName() );
+        return index2Name;
     }
 
     @Override

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

@@ -20,6 +20,7 @@ package org.mapstruct.ap.internal.model;
 
 import static org.mapstruct.ap.internal.util.Collections.first;
 
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -143,6 +144,7 @@ public abstract class ContainerMappingMethodBuilder<B extends ContainerMappingMe
 
         return instantiateMappingMethod(
             method,
+            existingVariables,
             assignment,
             factoryMethod,
             mapNullToDefault,
@@ -153,7 +155,8 @@ public abstract class ContainerMappingMethodBuilder<B extends ContainerMappingMe
         );
     }
 
-    protected abstract M instantiateMappingMethod(Method method, Assignment assignment, MethodReference factoryMethod,
+    protected abstract M instantiateMappingMethod(Method method, Collection<String> existingVariables,
+                                                  Assignment assignment, MethodReference factoryMethod,
                                                   boolean mapNullToDefault, String loopVariableName,
                                                   List<LifecycleCallbackMethodReference> beforeMappingMethods,
                                                   List<LifecycleCallbackMethodReference> afterMappingMethods,

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

@@ -20,6 +20,7 @@ package org.mapstruct.ap.internal.model;
 
 import static org.mapstruct.ap.internal.util.Collections.first;
 
+import java.util.Collection;
 import java.util.List;
 
 import org.mapstruct.ap.internal.model.assignment.Assignment;
@@ -62,12 +63,13 @@ public class IterableMappingMethod extends ContainerMappingMethod {
         }
 
         @Override
-        protected IterableMappingMethod instantiateMappingMethod(Method method, Assignment assignment,
+        protected IterableMappingMethod instantiateMappingMethod(Method method, Collection<String> existingVariables,
-            MethodReference factoryMethod, boolean mapNullToDefault, String loopVariableName,
+            Assignment assignment, MethodReference factoryMethod, boolean mapNullToDefault, String loopVariableName,
             List<LifecycleCallbackMethodReference> beforeMappingMethods,
             List<LifecycleCallbackMethodReference> afterMappingMethods, SelectionParameters selectionParameters) {
             return new IterableMappingMethod(
                 method,
+                existingVariables,
                 assignment,
                 factoryMethod,
                 mapNullToDefault,
@@ -79,13 +81,14 @@ public class IterableMappingMethod extends ContainerMappingMethod {
         }
     }
 
-    private IterableMappingMethod(Method method, Assignment parameterAssignment, MethodReference factoryMethod,
+    private IterableMappingMethod(Method method, Collection<String> existingVariables, Assignment parameterAssignment,
-                                  boolean mapNullToDefault, String loopVariableName,
+                                  MethodReference factoryMethod, boolean mapNullToDefault, String loopVariableName,
                                   List<LifecycleCallbackMethodReference> beforeMappingReferences,
                                   List<LifecycleCallbackMethodReference> afterMappingReferences,
         SelectionParameters selectionParameters) {
         super(
             method,
+            existingVariables,
             parameterAssignment,
             factoryMethod,
             mapNullToDefault,

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

@@ -18,6 +18,7 @@
  */
 package org.mapstruct.ap.internal.model;
 
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
@@ -161,6 +162,7 @@ public class MapMappingMethod extends NormalTypeMappingMethod {
 
             return new MapMappingMethod(
                 method,
+                existingVariables,
                 keyAssignment,
                 valueAssignment,
                 factoryMethod,
@@ -176,11 +178,12 @@ public class MapMappingMethod extends NormalTypeMappingMethod {
         }
     }
 
-    private MapMappingMethod(Method method, Assignment keyAssignment, Assignment valueAssignment,
+    private MapMappingMethod(Method method, Collection<String> existingVariableNames, Assignment keyAssignment,
-                             MethodReference factoryMethod, boolean mapNullToDefault,
+                             Assignment valueAssignment, MethodReference factoryMethod, boolean mapNullToDefault,
                              List<LifecycleCallbackMethodReference> beforeMappingReferences,
                              List<LifecycleCallbackMethodReference> afterMappingReferences) {
-        super( method, factoryMethod, mapNullToDefault, beforeMappingReferences, afterMappingReferences );
+        super( method, existingVariableNames, factoryMethod, mapNullToDefault, beforeMappingReferences,
+            afterMappingReferences );
 
         this.keyAssignment = keyAssignment;
         this.valueAssignment = valueAssignment;

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

@@ -18,6 +18,7 @@
  */
 package org.mapstruct.ap.internal.model;
 
+import java.util.Collection;
 import java.util.List;
 import java.util.Set;
 
@@ -36,10 +37,11 @@ public abstract class NormalTypeMappingMethod extends MappingMethod {
     private final boolean overridden;
     private final boolean mapNullToDefault;
 
-    NormalTypeMappingMethod(Method method, MethodReference factoryMethod, boolean mapNullToDefault,
+    NormalTypeMappingMethod(Method method, Collection<String> existingVariableNames, MethodReference factoryMethod,
+        boolean mapNullToDefault,
         List<LifecycleCallbackMethodReference> beforeMappingReferences,
         List<LifecycleCallbackMethodReference> afterMappingReferences) {
-        super( method, beforeMappingReferences, afterMappingReferences );
+        super( method, existingVariableNames, beforeMappingReferences, afterMappingReferences );
         this.factoryMethod = factoryMethod;
         this.overridden = method.overridesMethod();
         this.mapNullToDefault = mapNullToDefault;

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

@@ -18,6 +18,7 @@
  */
 package org.mapstruct.ap.internal.model;
 
+import java.util.Collection;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Set;
@@ -60,8 +61,8 @@ public class StreamMappingMethod extends ContainerMappingMethod {
         }
 
         @Override
-        protected StreamMappingMethod instantiateMappingMethod(Method method, Assignment assignment,
+        protected StreamMappingMethod instantiateMappingMethod(Method method, Collection<String> existingVariables,
-            MethodReference factoryMethod, boolean mapNullToDefault, String loopVariableName,
+            Assignment assignment, MethodReference factoryMethod, boolean mapNullToDefault, String loopVariableName,
             List<LifecycleCallbackMethodReference> beforeMappingMethods,
             List<LifecycleCallbackMethodReference> afterMappingMethods, SelectionParameters selectionParameters) {
 
@@ -78,6 +79,7 @@ public class StreamMappingMethod extends ContainerMappingMethod {
 
             return new StreamMappingMethod(
                 method,
+                existingVariables,
                 assignment,
                 factoryMethod,
                 mapNullToDefault,
@@ -90,13 +92,14 @@ public class StreamMappingMethod extends ContainerMappingMethod {
         }
     }
 
-    private StreamMappingMethod(Method method, Assignment parameterAssignment, MethodReference factoryMethod,
+    private StreamMappingMethod(Method method, Collection<String> existingVariables, Assignment parameterAssignment,
-                                boolean mapNullToDefault, String loopVariableName,
+                                MethodReference factoryMethod, boolean mapNullToDefault, String loopVariableName,
                                 List<LifecycleCallbackMethodReference> beforeMappingReferences,
                                 List<LifecycleCallbackMethodReference> afterMappingReferences,
         SelectionParameters selectionParameters, Set<Type> helperImports) {
         super(
             method,
+            existingVariables,
             parameterAssignment,
             factoryMethod,
             mapNullToDefault,

processor/src/test/java/org/mapstruct/ap/test/bugs/_1111/Issue1111Mapper.java

@@ -0,0 +1,44 @@
+/**
+ *  Copyright 2012-2017 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._1111;
+
+import java.util.List;
+import org.mapstruct.Mapper;
+import org.mapstruct.factory.Mappers;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+@Mapper
+public interface Issue1111Mapper {
+
+    Issue1111Mapper INSTANCE = Mappers.getMapper( Issue1111Mapper.class );
+
+    Target toTarget(Source in);
+
+    List<Target> list(List<Source> in);
+
+    List<List<Target>> listList(List<List<Source>> in);
+
+    class Source { }
+
+    class Target { }
+
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_1111/Issue1111Test.java

@@ -0,0 +1,53 @@
+/**
+ *  Copyright 2012-2017 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._1111;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.util.Arrays;
+import java.util.List;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mapstruct.ap.test.bugs._1111.Issue1111Mapper.Source;
+import org.mapstruct.ap.test.bugs._1111.Issue1111Mapper.Target;
+import org.mapstruct.ap.testutil.IssueKey;
+import org.mapstruct.ap.testutil.WithClasses;
+import org.mapstruct.ap.testutil.runner.AnnotationProcessorTestRunner;
+
+/**
+ *
+ * @author Sjaak Derksen
+ */
+@IssueKey( "1111")
+@WithClasses({Issue1111Mapper.class})
+@RunWith(AnnotationProcessorTestRunner.class)
+public class Issue1111Test {
+
+    @Test
+    public void shouldCompile() {
+
+        List<List<Source>> source = Arrays.asList( Arrays.asList( new Source() ) );
+
+        List<List<Issue1111Mapper.Target>> target = Issue1111Mapper.INSTANCE.listList( source );
+
+        assertThat( target ).hasSize( 1 );
+        assertThat( target.get( 0 ) ).hasSize( 1 );
+        assertThat( target.get( 0 ).get( 0 ) ).isInstanceOf( Target.class );
+    }
+}