From 8fbbd7a3dea5002841a9cee39f630158744665a5 Mon Sep 17 00:00:00 2001
From: Tagir Valeev <Tagir.Valeev@jetbrains.com>
Date: Mon, 27 Apr 2020 17:17:35 +0700
Subject: [PATCH] Report nullable Map.get if map values are nullable

Part of IDEA-236740

GitOrigin-RevId: d507993271d302a7a5fb2e3d1aacb3274cea79b1
---
 .../com/intellij/codeInspection/dataFlow/DfaPsiUtil.java    | 2 +-
 ...WithNotNullKeys.java => MapGetWithValueNullability.java} | 6 ++++++
 .../java/codeInspection/DataFlowInspection8Test.java        | 2 +-
 3 files changed, 8 insertions(+), 2 deletions(-)
 rename java/java-tests/testData/inspection/dataFlow/fixture/{MapGetWithNotNullKeys.java => MapGetWithValueNullability.java} (65%)

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 ea771598b218..844bcdd86b20 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
@@ -104,7 +104,7 @@ public class DfaPsiUtil {
     }
 
     if (owner instanceof PsiMethod && isMapMethodWithUnknownNullity((PsiMethod)owner)) {
-      return Nullability.UNKNOWN;
+      return getTypeNullability(resultType) == Nullability.NULLABLE ? Nullability.NULLABLE : Nullability.UNKNOWN;
     }
 
     Nullability fromType = getTypeNullability(resultType);
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/MapGetWithNotNullKeys.java b/java/java-tests/testData/inspection/dataFlow/fixture/MapGetWithValueNullability.java
similarity index 65%
rename from java/java-tests/testData/inspection/dataFlow/fixture/MapGetWithNotNullKeys.java
rename to java/java-tests/testData/inspection/dataFlow/fixture/MapGetWithValueNullability.java
index 44ed68952ae2..98c1f62f48f8 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/MapGetWithNotNullKeys.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/MapGetWithValueNullability.java
@@ -8,6 +8,7 @@ class Test {
     if (value == null) {
       System.out.println("it's not contained");
     }
+    map.get("z").intValue();
 
     value = hashMap.get("y");
     if (value == null) {
@@ -15,6 +16,11 @@ class Test {
     }
   }
 
+  public void main1(Map<@NotNull String, @Nullable Integer> map, HashMap<@NotNull String, @Nullable Integer> hashMap) {
+    map.get("y").<warning descr="Method invocation 'intValue' may produce 'NullPointerException'">intValue</warning>();
+    hashMap.get("y").<warning descr="Method invocation 'intValue' may produce 'NullPointerException'">intValue</warning>();
+  }
+
   public void main2(Map<@NotNull String, @NotNull Integer> map, HashMap<@NotNull String, @NotNull Integer> hashMap) {
     Integer value = map.remove("y");
     if (value == null) {
diff --git a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection8Test.java b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection8Test.java
index f64d1e892354..94ca0ab68e25 100644
--- a/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection8Test.java
+++ b/java/java-tests/testSrc/com/intellij/java/codeInspection/DataFlowInspection8Test.java
@@ -197,7 +197,7 @@ public class DataFlowInspection8Test extends DataFlowInspectionTestCase {
   public void testStreamCustomSumMethod() { doTest(); }
   public void testStreamReduceLogicalAnd() { doTest(); }
   
-  public void testMapGetWithNotNullKeys() { doTestWithCustomAnnotations(); }
+  public void testMapGetWithValueNullability() { doTestWithCustomAnnotations(); }
   public void testInferNestedForeachNullability() { doTestWithCustomAnnotations(); }
 
   public void testMethodVsExpressionTypeAnnotationConflict() {