PY-19028 Fixed: Byte slices return incorrect type inference

Update skeletons to have correct return type for bytes.__getitem__

python/helpers/python-skeletons/builtins.py

@@ -980,7 +980,7 @@ class bytes(object):
         """y-th item of x, origin 0.
 
         :type y: numbers.Integral
-        :rtype: int
+        :rtype: int | bytes
         """
         return 0
 

python/testData/inspections/PyUnresolvedReferencesInspection3K/decodeBytesAfterSlicing.py

@@ -0,0 +1,2 @@
+a = b'1234'[:3]
+print(a.decode('utf-8'))

python/testSrc/com/jetbrains/python/inspections/Py3UnresolvedReferencesInspectionTest.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2000-2013 JetBrains s.r.o.
+ * Copyright 2000-2016 JetBrains s.r.o.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -137,4 +137,9 @@ public class Py3UnresolvedReferencesInspectionTest extends PyTestCase {
   public void testNoMostDerivedMetaClass() {
     doTest();
   }
+
+  // PY-19028
+  public void testDecodeBytesAfterSlicing() {
+    doTest();
+  }
 }