commit cad7abf8abe657b696b9c8deb4b727e0cefaf36d
author Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Wed Sep 04 15:18:05 2019 -0700
committer GitHub <noreply@github.com> Wed Sep 04 15:18:05 2019 -0700
tree 45548b080b6d87eebf33c63f16e27c8a4059c016
parent 5e194f57c08898cb8da457c6584402a2be2c828d

bpo-38030: Fix os.stat failures on block devices on Windows (GH-15681)

(cherry picked from commit 772ec0fad57412daa53d16d7019b6b2fe6e94942)

Co-authored-by: Steve Dower <steve.dower@python.org>

Modules/posixmodule.c

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index b9e8c0d..771c561 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -1793,13 +1793,13 @@
             case ERROR_INVALID_PARAMETER:
             case ERROR_INVALID_FUNCTION:
             case ERROR_NOT_SUPPORTED:
-                retval = -1;
+                /* Volumes and physical disks are block devices, e.g.
+                   \\.\C: and \\.\PhysicalDrive0. */
+                memset(result, 0, sizeof(*result));
+                result->st_mode = 0x6000; /* S_IFBLK */
                 goto cleanup;
             }
-            /* Volumes and physical disks are block devices, e.g.
-               \\.\C: and \\.\PhysicalDrive0. */
-            memset(result, 0, sizeof(*result));
-            result->st_mode = 0x6000; /* S_IFBLK */
+            retval = -1;
             goto cleanup;
         }
     }
@@ -1826,7 +1826,14 @@
 
 cleanup:
     if (hFile != INVALID_HANDLE_VALUE) {
-        CloseHandle(hFile);
+        /* Preserve last error if we are failing */
+        error = retval ? GetLastError() : 0;
+        if (!CloseHandle(hFile)) {
+            retval = -1;
+        } else if (retval) {
+            /* Restore last error */
+            SetLastError(error);
+        }
     }
 
     return retval;