From: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com>
Date: Mon, 13 Nov 2023 16:25:01 +0000 (+0100)
Subject: gh-111856: Fix os.fstat on windows with FAT32 and exFAT filesystem (GH-112038)
X-Git-Tag: v3.12.1~132
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=dfdbfc548f45dc254844b71f77f03136c413b76b;p=thirdparty%2FPython%2Fcpython.git

gh-111856: Fix os.fstat on windows with FAT32 and exFAT filesystem (GH-112038)

(cherry picked from commit 29af7369dbbbba8cefafb196e977bce8189a527d)

Co-authored-by: AN Long <aisk@users.noreply.github.com>
---

diff --git a/Misc/NEWS.d/next/Windows/2023-11-13-22-35-27.gh-issue-111856.vEtA5z.rst b/Misc/NEWS.d/next/Windows/2023-11-13-22-35-27.gh-issue-111856.vEtA5z.rst
new file mode 100644
index 000000000000..b1388df8e4c4
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2023-11-13-22-35-27.gh-issue-111856.vEtA5z.rst
@@ -0,0 +1,2 @@
+Fixes :func:`~os.fstat` on file systems that do not support file ID
+requests. This includes FAT32 and exFAT.
diff --git a/Python/fileutils.c b/Python/fileutils.c
index 610e729feb35..c7521751cd26 100644
--- a/Python/fileutils.c
+++ b/Python/fileutils.c
@@ -1236,6 +1236,7 @@ _Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
     BY_HANDLE_FILE_INFORMATION info;
     FILE_BASIC_INFO basicInfo;
     FILE_ID_INFO idInfo;
+    FILE_ID_INFO *pIdInfo = &idInfo;
     HANDLE h;
     int type;
 
@@ -1268,15 +1269,19 @@ _Py_fstat_noraise(int fd, struct _Py_stat_struct *status)
     }
 
     if (!GetFileInformationByHandle(h, &info) ||
-        !GetFileInformationByHandleEx(h, FileBasicInfo, &basicInfo, sizeof(basicInfo)) ||
-        !GetFileInformationByHandleEx(h, FileIdInfo, &idInfo, sizeof(idInfo))) {
+        !GetFileInformationByHandleEx(h, FileBasicInfo, &basicInfo, sizeof(basicInfo))) {
         /* The Win32 error is already set, but we also set errno for
            callers who expect it */
         errno = winerror_to_errno(GetLastError());
         return -1;
     }
 
-    _Py_attribute_data_to_stat(&info, 0, &basicInfo, &idInfo, status);
+    if (!GetFileInformationByHandleEx(h, FileIdInfo, &idInfo, sizeof(idInfo))) {
+        /* Failed to get FileIdInfo, so do not pass it along */
+        pIdInfo = NULL;
+    }
+
+    _Py_attribute_data_to_stat(&info, 0, &basicInfo, pIdInfo, status);
     return 0;
 #else
     return fstat(fd, status);