diamonds: fix conflicting names between constructor and class type parameters (rename the constructor type parameters)

java/java-psi-impl/src/com/intellij/psi/PsiDiamondTypeImpl.java

@@ -35,6 +35,7 @@ import com.intellij.psi.util.*;
 import com.intellij.util.Function;
 import com.intellij.util.IncorrectOperationException;
 import com.intellij.util.VisibilityUtil;
+import com.intellij.util.text.UniqueNameGenerator;
 import org.jetbrains.annotations.NonNls;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
@@ -353,6 +354,10 @@ public class PsiDiamondTypeImpl extends PsiDiamondType {
     }
     buf.append("static ");
     buf.append("<");
+    //it's possible that constructor type parameters and class type parameters are same named:
+    //it's important that class type parameters names are preserved(they are first in the list),
+    //though constructor parameters would be renamed in case of conflicts
+    final UniqueNameGenerator generator = new UniqueNameGenerator();
     buf.append(StringUtil.join(params, new Function<PsiTypeParameter, String>() {
       @Override
       public String fun(PsiTypeParameter psiTypeParameter) {
@@ -369,7 +374,7 @@ public class PsiDiamondTypeImpl extends PsiDiamondType {
             extendsList = " extends " + StringUtil.join(extendsListTypes, canonicalTypePresentationFun, "&");
           }
         }
-        return psiTypeParameter.getName() + extendsList;
+        return generator.generateUniqueName(psiTypeParameter.getName()) + extendsList;
       }
     }, ", "));
     buf.append(">");
@@ -430,10 +435,10 @@ public class PsiDiamondTypeImpl extends PsiDiamondType {
 
   private static PsiTypeParameter[] getAllTypeParams(PsiTypeParameterListOwner listOwner, PsiClass containingClass) {
     Set<PsiTypeParameter> params = new LinkedHashSet<PsiTypeParameter>();
+    Collections.addAll(params, containingClass.getTypeParameters());
     if (listOwner != null) {
       Collections.addAll(params, listOwner.getTypeParameters());
     }
-    Collections.addAll(params, containingClass.getTypeParameters());
     return params.toArray(new PsiTypeParameter[params.size()]);
   }
 

java/java-tests/testData/codeInsight/daemonCodeAnalyzer/lambda/diamond/ConflictingNamesInConstructorAndClassTypeParameters.java

@@ -0,0 +1,12 @@
+
+interface E {}
+interface A<T> {}
+class N<P extends E> implements A<P> {
+  <P extends E> N(P p) {}
+}
+
+class K {
+  <J extends E> A<J> f(J p) {
+    return new N<>(p);
+  }
+}

java/java-tests/testSrc/com/intellij/codeInsight/daemon/lambda/Diamond8HighlightingTest.java

@@ -69,6 +69,10 @@ public class Diamond8HighlightingTest extends LightDaemonAnalyzerTestCase {
     doTest();
   }
 
+  public void testConflictingNamesInConstructorAndClassTypeParameters() throws Exception {
+    doTest();
+  }
+
   private void doTest() throws Exception {
     doTest(BASE_PATH + "/" + getTestName(false) + ".java", false, false);
   }