encode qualifiers in method refs (IDEA-145512)

java/java-impl/src/com/intellij/psi/impl/source/tree/JavaTreeCopyHandler.java

@@ -27,6 +27,7 @@ import com.intellij.psi.codeStyle.JavaCodeStyleManager;
 import com.intellij.psi.impl.source.PsiJavaCodeReferenceElementImpl;
 import com.intellij.psi.impl.source.SourceTreeToPsiMap;
 import com.intellij.psi.templateLanguages.OuterLanguageElement;
+import com.intellij.psi.tree.IElementType;
 import com.intellij.util.IncorrectOperationException;
 
 import java.util.Map;
@@ -38,8 +39,10 @@ public class JavaTreeCopyHandler implements TreeCopyHandler {
   public TreeElement decodeInformation(TreeElement element, final Map<Object, Object> decodingState) {
     boolean shallDecodeEscapedTexts = shallEncodeEscapedTexts(element, decodingState);
     if (element instanceof CompositeElement) {
-      if (element.getElementType() == JavaElementType.JAVA_CODE_REFERENCE ||
-          element.getElementType() == JavaElementType.REFERENCE_EXPRESSION) {
+      final IElementType elementType = element.getElementType();
+      if (elementType == JavaElementType.JAVA_CODE_REFERENCE ||
+          elementType == JavaElementType.REFERENCE_EXPRESSION ||
+          elementType == JavaElementType.METHOD_REF_EXPRESSION) {
         PsiJavaCodeReferenceElement ref = (PsiJavaCodeReferenceElement)SourceTreeToPsiMap.treeElementToPsi(element);
         final PsiClass refClass = element.getCopyableUserData(JavaTreeGenerator.REFERENCED_CLASS_KEY);
         if (refClass != null) {
@@ -190,7 +193,8 @@ public class JavaTreeCopyHandler implements TreeCopyHandler {
       final JavaResolveResult resolveResult = javaRefElement.advancedResolve(false);
       final PsiElement target = resolveResult.getElement();
       if (target instanceof PsiClass &&
-          original.getTreeParent().getElementType() == JavaElementType.REFERENCE_EXPRESSION) {
+          (original.getTreeParent().getElementType() == JavaElementType.REFERENCE_EXPRESSION ||
+           original.getTreeParent().getElementType() == JavaElementType.METHOD_REF_EXPRESSION)) {
         ref.putCopyableUserData(JavaTreeGenerator.REFERENCED_CLASS_KEY, (PsiClass)target);
       }
       else if ((target instanceof PsiMethod || target instanceof PsiField) &&

java/java-tests/testData/refactoring/inlineMethod/multifile/decodeQualifierInMethodReference/after/Bar.java

@@ -0,0 +1,9 @@
+import java.util.Map;
+import java.util.Set;
+
+public class Bar {
+  void bar() {
+      Function<Map.Entry<Long, Set<Integer>>, Long> getKey = Map.Entry::getKey;
+
+  }
+}

java/java-tests/testData/refactoring/inlineMethod/multifile/decodeQualifierInMethodReference/after/Foo.java

@@ -0,0 +1,7 @@
+
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.function.Function;
+
+class Foo {
+}

java/java-tests/testData/refactoring/inlineMethod/multifile/decodeQualifierInMethodReference/before/Bar.java

@@ -0,0 +1,5 @@
+public class Bar {
+  void bar() {
+    Foo.foo();
+  }
+}

java/java-tests/testData/refactoring/inlineMethod/multifile/decodeQualifierInMethodReference/before/Foo.java

@@ -0,0 +1,12 @@
+
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.function.Function;
+
+class Foo {
+  public static void foo() {
+
+    Function<Entry<Long, Set<Integer>>, Long> getKey = Entry::getKey;
+
+  }
+}

java/java-tests/testSrc/com/intellij/refactoring/inline/InlineMethodMultifileTest.java

@@ -46,6 +46,10 @@ public class InlineMethodMultifileTest extends RefactoringTestCase {
     doTest("Foo", "foo");
   }
 
+  public void testDecodeQualifierInMethodReference() throws Exception {
+    doTest("Foo", "foo");
+  }
+
   private void doTest(String className, String methodName) throws Exception {
     String rootBefore = getRoot() + "/before";
     PsiTestUtil.removeAllRoots(myModule, IdeaTestUtil.getMockJdk17());