From 60e0db2a5cb60904ed3d2f6de0f59fc62824fd57 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Mon, 21 Nov 2016 16:06:00 +0100
Subject: [PATCH] IDEA-163989 IDEA reports Object.getClass() with wrong return
 type for generic parameters

---
 .../completion/MemberLookupHelper.java        | 19 ++++++++++++++++++-
 .../completion/normal/GetClassType.java       |  5 +++++
 .../completion/NormalCompletionTest.groovy    |  5 +++++
 3 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 java/java-tests/testData/codeInsight/completion/normal/GetClassType.java

diff --git a/java/java-impl/src/com/intellij/codeInsight/completion/MemberLookupHelper.java b/java/java-impl/src/com/intellij/codeInsight/completion/MemberLookupHelper.java
index cd338c747c86..2f362b4898cc 100644
--- a/java/java-impl/src/com/intellij/codeInsight/completion/MemberLookupHelper.java
+++ b/java/java-impl/src/com/intellij/codeInsight/completion/MemberLookupHelper.java
@@ -20,9 +20,13 @@ import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
 import com.intellij.psi.util.PsiFormatUtil;
 import com.intellij.psi.util.PsiFormatUtilBase;
+import com.intellij.psi.util.PsiTypesUtil;
+import com.intellij.psi.util.TypeConversionUtil;
+import com.intellij.util.containers.ContainerUtil;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
+import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -89,12 +93,25 @@ public class MemberLookupHelper {
       presentation.appendTailText(location, true);
     }
 
-    final PsiType type = myMember instanceof PsiMethod ? ((PsiMethod)myMember).getReturnType() : ((PsiField) myMember).getType();
+    PsiType declaredType = myMember instanceof PsiMethod ? ((PsiMethod)myMember).getReturnType() : ((PsiField)myMember).getType();
+    PsiType type = patchGetClass(substitutor.substitute(declaredType));
     if (type != null) {
       presentation.setTypeText(substitutor.substitute(type).getPresentableText());
     }
   }
 
+  @Nullable
+  private PsiType patchGetClass(@Nullable PsiType type) {
+    if (myMember instanceof PsiMethod && PsiTypesUtil.isGetClass((PsiMethod)myMember) && type instanceof PsiClassType) {
+      PsiType arg = ContainerUtil.getFirstItem(Arrays.asList(((PsiClassType)type).getParameters()));
+      PsiType bound = arg instanceof PsiWildcardType ? TypeConversionUtil.erasure(((PsiWildcardType)arg).getExtendsBound()) : null;
+      if (bound != null) {
+        return PsiTypesUtil.createJavaLangClassType(myMember, bound, false);
+      }
+    }
+    return type;
+  }
+
   @NotNull
   static String getMethodParameterString(@NotNull PsiMethod method, @NotNull PsiSubstitutor substitutor) {
     return PsiFormatUtil.formatMethod(method, substitutor,
diff --git a/java/java-tests/testData/codeInsight/completion/normal/GetClassType.java b/java/java-tests/testData/codeInsight/completion/normal/GetClassType.java
new file mode 100644
index 000000000000..2b89e81fb824
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/normal/GetClassType.java
@@ -0,0 +1,5 @@
+class F {
+    <R extends Number> void foo(R r) {
+        r.getCl<caret>a
+    }
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy b/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy
index f131f38a8c82..2baf0de8f1bc 100644
--- a/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy
+++ b/java/java-tests/testSrc/com/intellij/codeInsight/completion/NormalCompletionTest.groovy
@@ -1730,4 +1730,9 @@ class Bar {
 
   void testCopyConstructor() { doTest('\n') }
 
+  void testGetClassType() {
+    configure()
+    assert 'Class<? extends Number>' == LookupElementPresentation.renderElement(myFixture.lookupElements[0]).typeText
+  }
+
 }