From 9f46e01c8867f1d7ab00294fcd3afd23b6f48b4c Mon Sep 17 00:00:00 2001
From: "Ilya.Kazakevich" <Ilya.Kazakevich@jetbrains.com>
Date: Tue, 13 Dec 2016 17:47:27 +0300
Subject: [PATCH] PY-21339: Use AppConfig for INSTALLED_APPS for Django 1.9+

 * AppConfig added
 * #getTopLevelClasses() marked @NotNull since the only implementation is @NotNull
 * QualifiedNameResolverImpl verbosity improved
---
 python/psi-api/src/com/jetbrains/python/psi/PyFile.java         | 1 +
 python/src/com/jetbrains/python/psi/impl/PyFileImpl.java        | 1 +
 .../jetbrains/python/psi/resolve/QualifiedNameResolverImpl.java | 2 +-
 3 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/python/psi-api/src/com/jetbrains/python/psi/PyFile.java b/python/psi-api/src/com/jetbrains/python/psi/PyFile.java
index 2640a4f31c4f..cc00bb02efee 100644
--- a/python/psi-api/src/com/jetbrains/python/psi/PyFile.java
+++ b/python/psi-api/src/com/jetbrains/python/psi/PyFile.java
@@ -27,6 +27,7 @@ import java.util.List;
 public interface PyFile extends PyElement, PsiFile, PyDocStringOwner, ScopeOwner {
   List<PyStatement> getStatements();
 
+  @NotNull
   List<PyClass> getTopLevelClasses();
 
   @NotNull
diff --git a/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java b/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java
index 74d2081c7c12..f06a73791f69 100644
--- a/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java
+++ b/python/src/com/jetbrains/python/psi/impl/PyFileImpl.java
@@ -367,6 +367,7 @@ public class PyFileImpl extends PsiFileBase implements PyFile, PyExpression {
   }
 
   @Override
+  @NotNull
   public List<PyClass> getTopLevelClasses() {
     return PyPsiUtils.collectStubChildren(this, getStub(), PyElementTypes.CLASS_DECLARATION);
   }
diff --git a/python/src/com/jetbrains/python/psi/resolve/QualifiedNameResolverImpl.java b/python/src/com/jetbrains/python/psi/resolve/QualifiedNameResolverImpl.java
index d9d8a1e14ef0..e0fca1c33552 100644
--- a/python/src/com/jetbrains/python/psi/resolve/QualifiedNameResolverImpl.java
+++ b/python/src/com/jetbrains/python/psi/resolve/QualifiedNameResolverImpl.java
@@ -393,7 +393,7 @@ public class QualifiedNameResolverImpl implements RootVisitor, QualifiedNameReso
       RootVisitorHost.visitSdkRoots(myContext.getSdk(), this);
     }
     else {
-      throw new IllegalStateException();
+      throw new IllegalStateException("Context is empty. Provide some context: module, file, sdk, etc");
     }
   }