WindowsError.str should display the windows error code,
not the posix error code; with test.
Fixes #1576174.

Will backport to release25-maint.
diff --git a/Lib/test/test_exceptions.py b/Lib/test/test_exceptions.py
index 585d6fe..79fcee3 100644
--- a/Lib/test/test_exceptions.py
+++ b/Lib/test/test_exceptions.py
@@ -183,6 +183,19 @@
             test_capi1()
             test_capi2()
 
+    def test_WindowsError(self):
+        try:
+            WindowsError
+        except NameError:
+            pass
+        else:
+            self.failUnlessEqual(str(WindowsError(1001)),
+                                 "1001")
+            self.failUnlessEqual(str(WindowsError(1001, "message")),
+                                 "[Error 1001] message")
+            self.failUnlessEqual(WindowsError(1001, "message").errno, 22)
+            self.failUnlessEqual(WindowsError(1001, "message").winerror, 1001)
+
     def testAttributes(self):
         # test that exception attributes are happy
 
diff --git a/Misc/NEWS b/Misc/NEWS
index ab3bf3f..b9b9883 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,9 @@
 Core and builtins
 -----------------
 
+- Bug #1576174: WindowsError now displays the windows error code
+  again, no longer the posix error code.
+
 - Patch #1549049: Support long values in structmember, issue warnings
   if the assigned value for structmember fields gets truncated.
 
diff --git a/Objects/exceptions.c b/Objects/exceptions.c
index c0b813d..0cd819c 100644
--- a/Objects/exceptions.c
+++ b/Objects/exceptions.c
@@ -828,9 +828,9 @@
             return NULL;
         }
 
-        if (self->myerrno) {
-            Py_INCREF(self->myerrno);
-            PyTuple_SET_ITEM(tuple, 0, self->myerrno);
+        if (self->winerror) {
+            Py_INCREF(self->winerror);
+            PyTuple_SET_ITEM(tuple, 0, self->winerror);
         }
         else {
             Py_INCREF(Py_None);
@@ -852,7 +852,7 @@
         Py_DECREF(fmt);
         Py_DECREF(tuple);
     }
-    else if (self->myerrno && self->strerror) {
+    else if (self->winerror && self->strerror) {
         PyObject *fmt;
         PyObject *tuple;
 
@@ -866,9 +866,9 @@
             return NULL;
         }
 
-        if (self->myerrno) {
-            Py_INCREF(self->myerrno);
-            PyTuple_SET_ITEM(tuple, 0, self->myerrno);
+        if (self->winerror) {
+            Py_INCREF(self->winerror);
+            PyTuple_SET_ITEM(tuple, 0, self->winerror);
         }
         else {
             Py_INCREF(Py_None);