From 1475442c3f051990c4934fdc34c0c58b50dd296b Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Tue, 19 Apr 2016 11:16:32 +0200
Subject: [PATCH] IDEA-154811 Nullable inspection is incorrect with
 user-defined valueOf static method in Enum

---
 .../codeInspection/dataFlow/DfaPsiUtil.java   | 23 ++++++++++++-------
 .../dataFlow/fixture/EnumConstantNotNull.java | 14 ++++++++++-
 2 files changed, 28 insertions(+), 9 deletions(-)

diff --git a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaPsiUtil.java b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaPsiUtil.java
index 2477f130d167..ed5d849ae81f 100644
--- a/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaPsiUtil.java
+++ b/java/java-analysis-impl/src/com/intellij/codeInspection/dataFlow/DfaPsiUtil.java
@@ -73,14 +73,8 @@ public class DfaPsiUtil {
     if (owner instanceof PsiEnumConstant || PsiUtil.isAnnotationMethod(owner)) {
       return Nullness.NOT_NULL;
     }
-    if (owner instanceof PsiMethod) {
-      PsiMethod method = (PsiMethod)owner;
-      if ("valueOf".equals(method.getName()) && method.hasModifierProperty(PsiModifier.STATIC)) {
-        PsiClass containingClass = method.getContainingClass();
-        if (containingClass != null && containingClass.isEnum()) {
-          return Nullness.NOT_NULL;
-        }
-      }
+    if (owner instanceof PsiMethod && isEnumValueOf((PsiMethod)owner)) {
+      return Nullness.NOT_NULL;
     }
 
     if (resultType != null) {
@@ -111,6 +105,19 @@ public class DfaPsiUtil {
     return Nullness.UNKNOWN;
   }
 
+  private static boolean isEnumValueOf(PsiMethod method) {
+    if ("valueOf".equals(method.getName()) && method.hasModifierProperty(PsiModifier.STATIC)) {
+      PsiClass containingClass = method.getContainingClass();
+      if (containingClass != null && containingClass.isEnum()) {
+        PsiParameter[] parameters = method.getParameterList().getParameters();
+        if (parameters.length == 1 && parameters[0].getType().equalsToText(CommonClassNames.JAVA_LANG_STRING)) {
+          return true;
+        }
+      }
+    }
+    return false;
+  }
+
   public static boolean isInitializedNotNull(PsiField field) {
     PsiClass containingClass = field.getContainingClass();
     if (containingClass == null) return false;
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/EnumConstantNotNull.java b/java/java-tests/testData/inspection/dataFlow/fixture/EnumConstantNotNull.java
index 8df81fa8f737..81ee0e6c1932 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/EnumConstantNotNull.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/EnumConstantNotNull.java
@@ -16,12 +16,24 @@ class FooWithComments {
     return <warning descr="Condition 'AnEnum.valueOf(name) != null' is always 'true'">AnEnum.valueOf(name) != null</warning>;
   }
 
+  boolean checkCustomValueOf(int i) {
+    return AnEnum.valueOf(i) != null;
+  }
+
   private native void anotherMethod(String name);
 
   @Nullable
   private native AnEnum nullableGetter();
 
   enum AnEnum {
-    ENUM_VALUE, FOO2
+    ENUM_VALUE, FOO2;
+
+    @Nullable
+    public static AnEnum valueOf(int i) {
+      if (i < 0 || i > 1)
+        return null;
+
+      return values()[i];
+    }
   }
 }