#2001 Avoid NPE when checking whether import type element is nested

When the typeToAdd is an array then TypeElement is null and ComponentType is the one that would be imported

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

@@ -288,10 +288,17 @@ public abstract class GeneratedType extends ModelElement {
             }
 
             if ( typeToAdd.getPackageName().equals( packageName ) ) {
+                if ( typeToAdd.getTypeElement() != null ) {
                     if ( !typeToAdd.getTypeElement().getNestingKind().isNested() ) {
                         return false;
                     }
                 }
+                else if ( typeToAdd.getComponentType() != null ) {
+                    if ( !typeToAdd.getComponentType().getTypeElement().getNestingKind().isNested() ) {
+                        return false;
+                    }
+                }
+            }
         }
 
         return true;

processor/src/test/java/org/mapstruct/ap/test/bugs/_2001/Entity.java

@@ -0,0 +1,25 @@
+/*
+ * 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._2001;
+
+import java.util.Set;
+
+/**
+ * @author Filip Hrisafov
+ */
+public
+class Entity {
+
+    private Set<EntityExtra> extras;
+
+    public Set<EntityExtra> getExtras() {
+        return extras;
+    }
+
+    public void setExtras(Set<EntityExtra> extras) {
+        this.extras = extras;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2001/EntityExtra.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._2001;
+
+/**
+ * @author Filip Hrisafov
+ */
+public
+class EntityExtra {
+
+    private String value;
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2001/Form.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._2001;
+
+/**
+ * @author Filip Hrisafov
+ */
+public
+class Form {
+
+    private FormExtra[] extras;
+
+    public FormExtra[] getExtras() {
+        return extras;
+    }
+
+    public void setExtras(FormExtra[] extras) {
+        this.extras = extras;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2001/FormExtra.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._2001;
+
+/**
+ * @author Filip Hrisafov
+ */
+public
+class FormExtra {
+
+    private String value;
+
+    public String getValue() {
+        return value;
+    }
+
+    public void setValue(String value) {
+        this.value = value;
+    }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2001/Issue2001Mapper.java

@@ -0,0 +1,17 @@
+/*
+ * 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._2001;
+
+import org.mapstruct.Mapper;
+
+/**
+ * @author Filip Hrisafov
+ */
+@Mapper
+public interface Issue2001Mapper {
+
+    Form map(Entity entity);
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_2001/Issue2001Test.java

@@ -0,0 +1,32 @@
+/*
+ * 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._2001;
+
+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;
+
+/**
+ * @author Filip Hrisafov
+ */
+@IssueKey("2001")
+@RunWith( AnnotationProcessorTestRunner.class )
+@WithClasses( {
+    Entity.class,
+    EntityExtra.class,
+    Form.class,
+    FormExtra.class,
+    Issue2001Mapper.class
+} )
+public class Issue2001Test {
+
+    @Test
+    public void shouldCompile() {
+
+    }
+}