decode: don't qualify 'ambiguous' reference if qualifier is available through inheritance (IDEA-142703)

java/java-psi-impl/src/com/intellij/codeInsight/ChangeContextUtil.java

@@ -202,7 +202,10 @@ public class ChangeContextUtil {
         if (refMember.hasModifierProperty(PsiModifier.STATIC)){
           PsiElement refElement = refExpr.resolve();
           if (!manager.areElementsEquivalent(refMember, refElement)){
-            refExpr.setQualifierExpression(factory.createReferenceExpression(containingClass));
+            final PsiClass currentClass = PsiTreeUtil.getParentOfType(refExpr, PsiClass.class);
+            if (currentClass == null || !InheritanceUtil.isInheritorOrSelf(currentClass, containingClass, true)) {
+              refExpr.setQualifierExpression(factory.createReferenceExpression(containingClass));
+            }
           }
         }
         else {

java/java-tests/testData/refactoring/moveClass/qualifiedRef/after/p1/StaticMethod.java

@@ -0,0 +1,4 @@
+package p1;
+public class StaticMethod {
+    public static int bar() {return 1;}
+}

java/java-tests/testData/refactoring/moveClass/qualifiedRef/after/p2/Test.java

@@ -0,0 +1,12 @@
+package p2;
+import p1.StaticMethod;
+
+import java.math.BigDecimal;
+public class Test extends BigDecimal {
+    Test() {super(0);}
+    void test() {
+        valueOf(0);
+        valueOf(StaticMethod.bar());
+        valueOf(StaticMethod.bar());
+    }
+}

java/java-tests/testData/refactoring/moveClass/qualifiedRef/before/p1/StaticMethod.java

@@ -0,0 +1,4 @@
+package p1;
+public class StaticMethod {
+    public static int bar() {return 1;}
+}

java/java-tests/testData/refactoring/moveClass/qualifiedRef/before/p1/Test.java

@@ -0,0 +1,10 @@
+package p1;
+import java.math.BigDecimal;
+public class Test extends BigDecimal {
+    Test() {super(0);}
+    void test() {
+        valueOf(0);
+        valueOf(StaticMethod.bar());
+        valueOf(StaticMethod.bar());
+    }
+}

java/java-tests/testSrc/com/intellij/refactoring/MoveClassTest.java

@@ -89,6 +89,10 @@ public class MoveClassTest extends RefactoringTestCase {
   public void testUnusedImport() throws Exception {
     doTest("unusedImport", new String[]{"p2.F2"}, "p1");
   }
+  
+  public void testQualifiedReferenceAfterFailedMethodConflictResolution() throws Exception {
+    doTest("qualifiedRef", new String[]{"p1.Test"}, "p2");
+  }
 
   private void doTest(@NonNls String testName, @NonNls String[] classNames, @NonNls String newPackageName) throws Exception{
     String root = JavaTestUtil.getJavaTestDataPath() + "/refactoring/moveClass/" + testName;