Issue #12034: Fix bogus caching of result in check_GetFinalPathNameByHandle.

pitrou · pitrou · commit 06eecead03a7 · 2012-10-21T16:33:33.000+02:00
Patch by Atsuo Ishimoto.
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -59,6 +59,9 @@ Core and Builtins
 Library
 -------
 
+- Issue #12034: Fix bogus caching of result in check_GetFinalPathNameByHandle.
+  Patch by Atsuo Ishimoto.
+
 - Issue #16220: wsgiref now always calls close() on an iterable response.
   Patch by Brent Tubbs.
 
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
@@ -1390,7 +1390,7 @@ attributes_from_dir_w(LPCWSTR pszFile, BY_HANDLE_FILE_INFORMATION *info, ULONG *
 }
 
 /* Grab GetFinalPathNameByHandle dynamically from kernel32 */
-static int has_GetFinalPathNameByHandle = 0;
+static int has_GetFinalPathNameByHandle = -1;
 static DWORD (CALLBACK *Py_GetFinalPathNameByHandleW)(HANDLE, LPWSTR, DWORD,
                                                       DWORD);
 static int
@@ -1401,7 +1401,7 @@ check_GetFinalPathNameByHandle()
                                                    DWORD);
 
     /* only recheck */
-    if (!has_GetFinalPathNameByHandle)
+    if (-1 == has_GetFinalPathNameByHandle)
     {
         hKernel32 = GetModuleHandleW(L"KERNEL32");
         *(FARPROC*)&Py_GetFinalPathNameByHandleA = GetProcAddress(hKernel32,
