#1826: fixed null pointer in nested property mapping when using presence checking (#1827)

copyright.txt

@@ -23,6 +23,7 @@ Gervais Blaise - https://github.com/gervaisb
 Gunnar Morling - https://github.com/gunnarmorling
 Ivo Smid - https://github.com/bedla
 Jeff Smyth - https://github.com/smythie86
+Jonathan Kraska - https://github.com/jakraska
 Joshua Spoerri - https://github.com/spoerri
 Kevin Grüneberg - https://github.com/kevcodez
 Michael Pardo - https://github.com/pardom

processor/src/main/resources/org/mapstruct/ap/internal/model/NestedPropertyMappingMethod.ftl

@@ -12,7 +12,7 @@
     }
 <#list propertyEntries as entry>
     <#if entry.presenceCheckerName?? >
-    if ( !<@localVarName index=entry_index/>.${entry.presenceCheckerName}() ) {
+    if ( <#if entry_index != 0><@localVarName index=entry_index/> == null || </#if>!<@localVarName index=entry_index/>.${entry.presenceCheckerName}() ) {
         return ${returnType.null};
     }
     </#if>

processor/src/test/java/org/mapstruct/ap/test/bugs/_1826/Issue1826Mapper.java

@@ -0,0 +1,20 @@
+/*
+ * 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._1826;
+
+import org.mapstruct.Mapper;
+import org.mapstruct.Mapping;
+import org.mapstruct.factory.Mappers;
+
+@Mapper
+public interface Issue1826Mapper {
+
+  Issue1826Mapper INSTANCE = Mappers.getMapper( Issue1826Mapper.class );
+
+  @Mapping(target = "content", source = "sourceChild.content")
+  Target sourceAToTarget(SourceParent sourceParent);
+
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_1826/Issue1826Test.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._1826;
+
+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;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@RunWith(AnnotationProcessorTestRunner.class)
+@IssueKey("1826")
+@WithClasses({
+        SourceParent.class,
+        SourceChild.class,
+        Target.class,
+        Issue1826Mapper.class
+})
+public class Issue1826Test {
+
+  @Test
+  public void testNestedPropertyMappingChecksForNull() {
+    SourceParent sourceParent = new SourceParent();
+    sourceParent.setSourceChild( null );
+
+    Target result = Issue1826Mapper.INSTANCE.sourceAToTarget( sourceParent );
+    assertThat( result.getContent() ).isNull();
+  }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_1826/SourceChild.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._1826;
+
+public class SourceChild {
+
+  private String content;
+  private Boolean hasContent = false;
+
+  public String getContent() {
+    return content;
+  }
+
+  public void setContent(String content) {
+    this.content = content;
+    hasContent = true;
+  }
+
+  public Boolean hasContent() {
+    return hasContent;
+  }
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_1826/SourceParent.java

@@ -0,0 +1,26 @@
+/*
+ * 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._1826;
+
+public class SourceParent {
+
+  private SourceChild sourceChild;
+  private Boolean hasSourceChild = false;
+
+  public SourceChild getSourceChild() {
+    return sourceChild;
+  }
+
+  public void setSourceChild(SourceChild sourceChild) {
+    this.sourceChild = sourceChild;
+    this.hasSourceChild = true;
+  }
+
+  public Boolean hasSourceChild() {
+    return hasSourceChild;
+  }
+
+}

processor/src/test/java/org/mapstruct/ap/test/bugs/_1826/Target.java

@@ -0,0 +1,19 @@
+/*
+ * 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._1826;
+
+public class Target {
+
+  private String content;
+
+  public String getContent() {
+    return content;
+  }
+
+  public void setContent(String content) {
+    this.content = content;
+  }
+}