[reactos] 04/05: [MOUNTMGR] Fix interpretation of QueryDeviceInformation GptDriveLetter

[Pierre Schweitzer]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=e359a3c8881b1ebb1a960…

commit e359a3c8881b1ebb1a96080ba456c94d7f17f95c
Author:     Pierre Schweitzer <pierre(a)reactos.org>
AuthorDate: Sat Oct 19 16:53:45 2019 +0200
Commit:     Pierre Schweitzer <pierre(a)reactos.org>
CommitDate: Sat Oct 19 16:59:58 2019 +0200

    [MOUNTMGR] Fix interpretation of QueryDeviceInformation GptDriveLetter
    
    Being TRUE doesn't mean the device is GPT and has a drive letter. It just
    means that it's not a GPT device with GPT_BASIC_DATA_ATTRIBUTE_NO_DRIVE_LETTER
    attribute. In short, if TRUE, it means that the device can receive a drive
    letter mount point.
    
    This fixes MountMgrNextDriveLetterWorker bailing out for any attempt to
    assign a drive letter to a device.
---
 drivers/filters/mountmgr/device.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/filters/mountmgr/device.c b/drivers/filters/mountmgr/device.c
index 4f3f9d2974e..ec9a04d063d 100644
--- a/drivers/filters/mountmgr/device.c
+++ b/drivers/filters/mountmgr/device.c
@@ -524,11 +524,12 @@ MountMgrNextDriveLetterWorker(IN PDEVICE_EXTENSION DeviceExtension,
     }
 
     /* If we didn't find a drive letter online
-     * ensure there's no GPT drive letter nor no drive entry
+     * ensure this is not a no drive entry
+    * by querying GPT attributes & database
      */
     if (NextEntry == &(DeviceInformation->SymbolicLinksListHead))
     {
-        if (GptDriveLetter || HasNoDriveLetterEntry(DeviceInformation->UniqueId))
+        if (!GptDriveLetter || HasNoDriveLetterEntry(DeviceInformation->UniqueId))
         {
             DriveLetterInfo->DriveLetterWasAssigned = FALSE;
             DriveLetterInfo->CurrentDriveLetter = 0;