From 0c70c63d0a4aa66b9404b44ccf7381c13d7424ab Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Tue, 8 May 2018 17:50:47 +0200
Subject: [PATCH] IDEA-191500 Inappropriate 'Enum.valueOf()' Smart Type
 suggestion

---
 .../filters/types/AssignableFromFilter.java   | 20 +++++++++++++++++--
 .../NoUnrelatedMethodSuggestion.java          |  8 ++++++++
 .../completion/SmartType18CompletionTest.java |  6 ++++++
 .../completion/SmartTypeCompletionTest.java   |  4 ++++
 4 files changed, 36 insertions(+), 2 deletions(-)
 create mode 100644 java/java-tests/testData/codeInsight/completion/smartType/NoUnrelatedMethodSuggestion.java

diff --git a/java/java-impl/src/com/intellij/psi/filters/types/AssignableFromFilter.java b/java/java-impl/src/com/intellij/psi/filters/types/AssignableFromFilter.java
index 206ef5c7b4f0..d6d28cedc5ac 100644
--- a/java/java-impl/src/com/intellij/psi/filters/types/AssignableFromFilter.java
+++ b/java/java-impl/src/com/intellij/psi/filters/types/AssignableFromFilter.java
@@ -112,14 +112,30 @@ public class AssignableFromFilter implements ElementFilter{
                                                                                       expectedType,
                                                                                       false,
                                                                                       PsiUtil.getLanguageLevel(place));
-      if (substitutionForParameter != PsiType.NULL && !(substitutionForParameter instanceof PsiIntersectionType) &&
-        PsiUtil.resolveClassInClassTypeOnly(substitutionForParameter) != parameter) {
+      if (substitutionForParameter != PsiType.NULL &&
+          !isImpossibleIntersection(substitutionForParameter) &&
+          !extendsImpossibleIntersection(PsiUtil.resolveClassInClassTypeOnly(substitutionForParameter)) &&
+          PsiUtil.resolveClassInClassTypeOnly(substitutionForParameter) != parameter) {
         return true;
       }
     }
     return false;
   }
 
+  private static boolean extendsImpossibleIntersection(@Nullable PsiClass psiClass) {
+    if (psiClass instanceof PsiTypeParameter) {
+      PsiClassType[] supers = psiClass.getExtendsListTypes();
+      if (supers.length > 1) {
+        return isImpossibleIntersection(PsiIntersectionType.createIntersection(supers));
+      }
+    }
+    return false;
+  }
+
+  private static boolean isImpossibleIntersection(PsiType intersection) {
+    return intersection instanceof PsiIntersectionType && ((PsiIntersectionType)intersection).getConflictingConjunctsMessage() != null;
+  }
+
   public String toString(){
     return "assignable-from(" + (myType != null ? myType : myClassName) + ")";
   }
diff --git a/java/java-tests/testData/codeInsight/completion/smartType/NoUnrelatedMethodSuggestion.java b/java/java-tests/testData/codeInsight/completion/smartType/NoUnrelatedMethodSuggestion.java
new file mode 100644
index 000000000000..162d809daa77
--- /dev/null
+++ b/java/java-tests/testData/codeInsight/completion/smartType/NoUnrelatedMethodSuggestion.java
@@ -0,0 +1,8 @@
+class Foo {
+  {
+    Foo m = <caret>x;
+  }
+
+
+  static <TX extends Enum<TX>> TX valueOf(Class<TX> enumType, String name);
+}
\ No newline at end of file
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartType18CompletionTest.java b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartType18CompletionTest.java
index c40fae768d8c..02a6821afb32 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartType18CompletionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartType18CompletionTest.java
@@ -188,6 +188,12 @@ public void testConvertToObjectStream() {
     checkResultByFile("/" + getTestName(false) + "-out.java");
   }
 
+  public void testNoUnrelatedMethodSuggestion() {
+    configureByTestName();
+    myFixture.complete(CompletionType.SMART, 1);
+    assertOrderedEquals(myFixture.getLookupElementStrings(), "this");
+  }
+
   public void testInferFromReturnTypeWhenCompleteInsideArgList() {
     configureByTestName();
     myFixture.complete(CompletionType.SMART, 1);
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java
index a1bad259d229..b037ffecaf2d 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInsight/completion/SmartTypeCompletionTest.java
@@ -1282,4 +1282,8 @@ public class SmartTypeCompletionTest extends LightFixtureCompletionTestCase {
   public void testNewMapTypeArguments() { doTest(); }
   public void testNewMapObjectTypeArguments() { doTest(); }
 
+  public void testNoUnrelatedMethodSuggestion() {
+    configureByTestName();
+    assertOrderedEquals(myFixture.getLookupElementStrings(), "this");
+  }
 }