From 0bae70149a34e8e21c2f32c8967c1f4c8e7c8106 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Tue, 18 Aug 2015 19:49:14 +0200
Subject: [PATCH] IDEA-143937 Bogus warning by 'Constant conditions &
 exceptions' inspection within lambda expressions, due to JSR 305
 @TypeQualifierDefault annotation

---
 .../codeInsight/AnnotationTargetUtil.java     | 11 ++++++++
 ...ambdaParametersWithDefaultNullability.java | 26 +++++++++++++++++++
 .../ParametersAreNonnullByDefault.java        | 11 ++++++++
 .../DataFlowInspection8Test.java              |  7 +++++
 4 files changed, 55 insertions(+)
 create mode 100644 java/java-tests/testData/inspection/dataFlow/fixture/LambdaParametersWithDefaultNullability.java

diff --git a/java/java-psi-api/src/com/intellij/codeInsight/AnnotationTargetUtil.java b/java/java-psi-api/src/com/intellij/codeInsight/AnnotationTargetUtil.java
index c1a747fb3b03..79df7a9d64b5 100644
--- a/java/java-psi-api/src/com/intellij/codeInsight/AnnotationTargetUtil.java
+++ b/java/java-psi-api/src/com/intellij/codeInsight/AnnotationTargetUtil.java
@@ -85,6 +85,17 @@ public class AnnotationTargetUtil {
         return FIELD_TARGETS;
       }
       if (element instanceof PsiParameter) {
+        // PARAMETER applies only to formal parameters (methods & lambdas) and catch parameters
+        // see https://docs.oracle.com/javase/specs/jls/se8/html/jls-9.html#jls-9.6.4.1
+        PsiElement scope = element.getParent();
+        if (scope instanceof PsiForeachStatement) {
+          return LOCAL_VARIABLE_TARGETS;
+        }
+        if (scope instanceof PsiParameterList && scope.getParent() instanceof PsiLambdaExpression && 
+            ((PsiParameter)element).getTypeElement() == null) {
+          return TargetType.EMPTY_ARRAY;
+        }
+        
         return PARAMETER_TARGETS;
       }
       if (element instanceof PsiLocalVariable) {
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/LambdaParametersWithDefaultNullability.java b/java/java-tests/testData/inspection/dataFlow/fixture/LambdaParametersWithDefaultNullability.java
new file mode 100644
index 000000000000..e25d5ff501d7
--- /dev/null
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/LambdaParametersWithDefaultNullability.java
@@ -0,0 +1,26 @@
+import javax.annotation.*;
+
+@ParametersAreNonnullByDefault 
+class Test {
+  void foo() {
+    Intf i1 = (o) -> {
+      if (o == null) {
+        System.out.println();
+      }
+    };
+    Intf i2 = (Object o) -> {
+      if (<warning descr="Condition 'o == null' is always 'false'">o == null</warning>) {
+        System.out.println();
+      }
+    };
+    Intf i3 = (@Nullable Object o) -> {
+      if (o == null) {
+        System.out.println();
+      }
+    };
+  }
+}
+
+interface Intf {
+  void foo(Object o);
+}
\ No newline at end of file
diff --git a/java/java-tests/testData/inspection/dataFlow/fixture/ParametersAreNonnullByDefault.java b/java/java-tests/testData/inspection/dataFlow/fixture/ParametersAreNonnullByDefault.java
index 7dc2e51effe4..4c06b23c8f8b 100644
--- a/java/java-tests/testData/inspection/dataFlow/fixture/ParametersAreNonnullByDefault.java
+++ b/java/java-tests/testData/inspection/dataFlow/fixture/ParametersAreNonnullByDefault.java
@@ -14,6 +14,17 @@ class Some {
 
 }
 
+@javax.annotation.ParametersAreNonnullByDefault
+class CheckLoop {
+  void foo(Iterable<String> it) {
+    for (String s : it) {
+      if (s == null) { // it's not ElementType.PARAMETER, no warning here
+        System.out.println();
+      }
+    }
+  }
+}
+
 @javax.annotation.ParametersAreNonnullByDefault
 class NotNullClass {
   static void foo(String s) {}
diff --git a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspection8Test.java b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspection8Test.java
index 90f864e137d2..27319dfd6fe3 100644
--- a/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspection8Test.java
+++ b/java/java-tests/testSrc/com/intellij/codeInspection/DataFlowInspection8Test.java
@@ -98,4 +98,11 @@ public class DataFlowInspection8Test extends LightCodeInsightFixtureTestCase {
 
   public void testOptionalOfNullable() { doTest(); }
 
+  public void testLambdaParametersWithDefaultNullability() {
+    DataFlowInspectionTest.addJavaxNullabilityAnnotations(myFixture);
+    DataFlowInspectionTest.addJavaxDefaultNullabilityAnnotations(myFixture);
+
+    doTest();
+  }
+
 }