bug mhammond#752 - fix ERROR_BAD_LENGTH in GetFileInformationByHandle…

…Ex in x86 builds When called with FileBasicInfo, GetFileInformationByHandleEx may throw pywintypes.error(24, 'GetFileInformationByHandleEx', 'The program issued a command but the command length is incorrect.'). With some older SDKs an odd pragma pack(4) directive is issued in <winsock2.h> before including of <windows.h>: #if (!defined(_WIN64) && !defined(WIN32)) #include <pshpack4.h> #endif ...no pragma pack(pop) #include <windows.h> If windows.h has not been seen earlier, it gets compiled with non default alignment. This makes sizeof and layout of some structs incorrect, including FILE_BASIC_INFO used in GetFileInformationByHandleEx. Neither distutils nor setup.py defines 'WIN32' so we are affected. Among SDKs with this quirk are 7.0a, the one that goes with 'Visual C++ for Python 2.7' and apparently 7.1. SDK known to be not affected are 8.0 and 8.1 from VS2015-update3, but pythonwin's setup.py does not seem to support them now.
guodaochong · Jan 2, 2018 · 3623bff · 3623bff
1 parent 46daaec
commit 3623bff
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diff --git a/CHANGES.txt b/CHANGES.txt
@@ -6,6 +6,9 @@ However contributors are encouraged to add their own entries for their work.
 
 Since build 221:
 ----------------
+* win32file - fix ERROR_BAD_LENGTH in GetFileInformationByHandleEx
+  in x86 builds(issue #752, rbschk)
+
 * MakeModuleForTypelib no longer catches COM exceptions, so no longer can
   return None. This is what the docstring always claimed the behaviour was
   and makes things less error prone. If you explicitly call this function and

diff --git a/win32/src/win32file.i b/win32/src/win32file.i
@@ -27,6 +27,22 @@
 #ifndef _WIN32_WINNT
 #define _WIN32_WINNT 0x0600
 #endif
+
+// bug #752
+// Include windows.h before winsock2 because with older SDKs the latter may
+// include windows.h with wrong pragma pack directive in effect, making
+// incorrect sizeof and layout of some WINAPI structs.
+// One does not simple include windows.h before winsock2, because windows.h
+// pulls old winsock.h (MSDN: for historical reasons) which conflicts with
+// winsock2 causing compilation errors.
+// To avoid inclusion of winsock.h we define WIN32_LEAN_AND_MEAN macro to
+// drop some headers from compilation. We then have to explicitly include ole2
+// and windefs affected by the macro.
+#define WIN32_LEAN_AND_MEAN
+#include "windows.h"
+#include "ole2.h"
+#include "Winefs.h"
+
 #include "winsock2.h"
 #include "mswsock.h"
 #include "pywintypes.h"

diff --git a/win32/test/test_win32file.py b/win32/test/test_win32file.py
@@ -209,6 +209,37 @@ def testFileTimes(self):
             f.Close()
             os.unlink(filename)
 
+class TestGetFileInfoByHandleEx(unittest.TestCase):
+    __handle = __filename = None
+    def setUp(self):
+        fd, self.__filename = tempfile.mkstemp()
+        os.close(fd)
+
+    def tearDown(self):
+        if self.__handle is not None:
+            self.__handle.Close()
+        if self.__filename is not None:
+            try:
+                os.unlink(self.__filename)
+            except OSError:
+                pass
+        self.__handle = self.__filename = None
+
+    def testFileBasicInfo(self):
+        attr = win32file.GetFileAttributes(self.__filename)
+        f = win32file.CreateFile(self.__filename, win32file.GENERIC_READ, 0, None,
+                                 win32con.OPEN_EXISTING, 0, None)
+        self.__handle = f
+        ct, at, wt = win32file.GetFileTime(f)
+
+        # bug #752: this throws ERROR_BAD_LENGTH (24) in x86 binaries of build 221
+        basic_info = win32file.GetFileInformationByHandleEx(f, win32file.FileBasicInfo)
+
+        self.assertEqual(ct, basic_info['CreationTime'])
+        self.assertEqual(at, basic_info['LastAccessTime'])
+        self.assertEqual(wt, basic_info['LastWriteTime'])
+        self.assertEqual(attr, basic_info['FileAttributes'])
+
 class TestOverlapped(unittest.TestCase):
     def testSimpleOverlapped(self):
         # Create a file in the %TEMP% directory.