From dc4b93db04f1b1b837ee207c5f1861fc4ae3a9b7 Mon Sep 17 00:00:00 2001
From: Semyon Proshev <Semyon.Proshev@jetbrains.com>
Date: Tue, 20 Mar 2018 18:02:40 +0300
Subject: [PATCH] Don't raise none assignment warning when return type is not
 None (PY-28729)

---
 .../inspections/PyNoneFunctionAssignmentInspection.java  | 2 +-
 .../Py3NoneFunctionAssignmentInspectionTest.java         | 9 +++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/python/src/com/jetbrains/python/inspections/PyNoneFunctionAssignmentInspection.java b/python/src/com/jetbrains/python/inspections/PyNoneFunctionAssignmentInspection.java
index 1acd71d36cda..40463b4c1b51 100644
--- a/python/src/com/jetbrains/python/inspections/PyNoneFunctionAssignmentInspection.java
+++ b/python/src/com/jetbrains/python/inspections/PyNoneFunctionAssignmentInspection.java
@@ -62,7 +62,7 @@ public class PyNoneFunctionAssignmentInspection extends PyInspection {
 
         if (type instanceof PyNoneType && callee != null) {
           final Condition<PyCallable> ignoredCallable = callable -> {
-            if (PySdkUtil.isElementInSkeletons(callable)) {
+            if (myTypeEvalContext.getReturnType(callable) != PyNoneType.INSTANCE || PySdkUtil.isElementInSkeletons(callable)) {
               return true;
             }
             if (callable instanceof PyFunction) {
diff --git a/python/testSrc/com/jetbrains/python/inspections/Py3NoneFunctionAssignmentInspectionTest.java b/python/testSrc/com/jetbrains/python/inspections/Py3NoneFunctionAssignmentInspectionTest.java
index b29b9cc6ffa9..8bbf463b582c 100644
--- a/python/testSrc/com/jetbrains/python/inspections/Py3NoneFunctionAssignmentInspectionTest.java
+++ b/python/testSrc/com/jetbrains/python/inspections/Py3NoneFunctionAssignmentInspectionTest.java
@@ -33,6 +33,15 @@ public class Py3NoneFunctionAssignmentInspectionTest extends PyInspectionTestCas
     doMultiFileTest();
   }
 
+  // PY-28729
+  public void testGenericSubstitutedWithNone() {
+    doTestByText(
+      "test1 = max([])\n" +
+      "test2 = max([], default=None)\n" +
+      "test3 = max([], default=0)"
+    );
+  }
+
   @NotNull
   @Override
   protected Class<? extends PyInspection> getInspectionClass() {