[core] work around a Windows bug where GetVolumePathNamesForVolumeName() can return the wrong drive letter

* A user is reporting that, on one of their platforms, Rufus is writing to the wrong target during the file-copy
  phase and using their existing Y: local drive instead of the drive associated to the USB, despite the fact
  that Rufus is passing the right volume name to GetVolumePathNamesForVolumeName().

* Here's the PowerShell wmic output, confirming that the volume GUID obtained by Rufus is the right one:

  DriveLetter : Y:
  DeviceId    : \\?\Volume{000349b1-17d0-69f6-c13f-f31162930600}\
  Capacity    : 118540464128
  FileSystem  : NTFS
  Label       : Y-DISK

  DriveLetter : H:
  DeviceId    : \\?\Volume{b150ff4a-d62b-11ea-86e3-f49634660e54}\
  Capacity    : 15791824896
  FileSystem  : FAT32
  Label       : ADATA16GB

* And here's the Rufus log demonstrating that GetVolumePathNamesForVolumeName() is returning the *WRONG* letter:

  Found volume \\?\Volume{b150ff4a-d62b-11ea-86e3-f49634660e54}\
  \\?\Volume{b150ff4a-d62b-11ea-86e3-f49634660e54}\ is already mounted as Y: instead of H: - Will now use this target instead...

* The last line shows, without the shadow of a doubt, that we did feed "\\?\Volume{b150ff4a-d62b-11ea-86e3-f49634660e54}\" to
  GetVolumePathNamesForVolumeName() and that this API call was successful (returned a non zero size) but ultimately returned
  the wrong letter (Y: instead of H:)...

* Therefore, Windows is BUGGY and the use of GetVolumePathNamesForVolumeName() must be avoided.

src/drive.c

@@ -1522,12 +1522,19 @@ BOOL MountVolume(char* drive_name, char *volume_name)
 {
 	char mounted_guid[52];
 	char mounted_letter[27] = { 0 };
+#if defined(WINDOWS_IS_NOT_BUGGY)
 	DWORD size;
+#endif
 
 	if ((drive_name == NULL) || (volume_name == NULL) || (drive_name[0] == '?') ||
 		(strncmp(volume_name, groot_name, groot_len) == 0))
 		return FALSE;
 
+	// Great: Windows has a *MAJOR BUG* whereas, in some circumstances, GetVolumePathNamesForVolumeName()
+	// can return the *WRONG* drive letter. And yes, we validated that this is *NOT* an issue like stack
+	// or buffer corruption and whatnot. It *IS* a Windows bug. So just drop the idea of updating the
+	// drive letter if already mounted and use the passed target always.
+#if defined(WINDOWS_IS_NOT_BUGGY)
 	// Windows may already have the volume mounted but under a different letter.
 	// If that is the case, update drive_name to that letter.
 	if ( (GetVolumePathNamesForVolumeNameA(volume_name, mounted_letter, sizeof(mounted_letter), &size))
@@ -1537,6 +1544,7 @@ BOOL MountVolume(char* drive_name, char *volume_name)
 		drive_name[0] = mounted_letter[0];
 		return TRUE;
 	}
+#endif
 
 	if (!SetVolumeMountPointA(drive_name, volume_name)) {
 		if (GetLastError() == ERROR_DIR_NOT_EMPTY) {

src/rufus.c

@@ -3479,12 +3479,12 @@ relaunch:
 			SendMessage(hMainDialog, WM_COMMAND, IDC_LOG, 0);
 			continue;
 		}
-#if defined(_DEBUG)
+#if defined(_DEBUG) || defined(TEST)
 		// Ctrl-T => Alternate Test mode that doesn't require a full rebuild
 		if ((ctrl_without_focus || ((GetKeyState(VK_CONTROL) & 0x8000) && (msg.message == WM_KEYDOWN)))
 			&& (msg.wParam == 'T')) {
-			extern int TestChecksum(void);
+			//extern int TestChecksum(void);
-			TestChecksum();
+			//TestChecksum();
 			continue;
 		}
 #endif

src/rufus.rc

@@ -33,7 +33,7 @@ LANGUAGE LANG_NEUTRAL, SUBLANG_NEUTRAL
 IDD_DIALOG DIALOGEX 12, 12, 232, 326
 STYLE DS_SETFONT | DS_MODALFRAME | DS_CENTER | WS_MINIMIZEBOX | WS_POPUP | WS_CAPTION | WS_SYSMENU
 EXSTYLE WS_EX_ACCEPTFILES
-CAPTION "Rufus 3.12.1693"
+CAPTION "Rufus 3.12.1694"
 FONT 9, "Segoe UI Symbol", 400, 0, 0x0
 BEGIN
     LTEXT           "Drive Properties",IDS_DRIVE_PROPERTIES_TXT,8,6,53,12,NOT WS_GROUP
@@ -395,8 +395,8 @@ END
 //
 
 VS_VERSION_INFO VERSIONINFO
- FILEVERSION 3,12,1693,0
+ FILEVERSION 3,12,1694,0
- PRODUCTVERSION 3,12,1693,0
+ PRODUCTVERSION 3,12,1694,0
  FILEFLAGSMASK 0x3fL
 #ifdef _DEBUG
  FILEFLAGS 0x1L
@@ -414,13 +414,13 @@ BEGIN
             VALUE "Comments", "https://rufus.ie"
             VALUE "CompanyName", "Akeo Consulting"
             VALUE "FileDescription", "Rufus"
-            VALUE "FileVersion", "3.12.1693"
+            VALUE "FileVersion", "3.12.1694"
             VALUE "InternalName", "Rufus"
             VALUE "LegalCopyright", "© 2011-2020 Pete Batard (GPL v3)"
             VALUE "LegalTrademarks", "https://www.gnu.org/licenses/gpl-3.0.html"
             VALUE "OriginalFilename", "rufus-3.12.exe"
             VALUE "ProductName", "Rufus"
-            VALUE "ProductVersion", "3.12.1693"
+            VALUE "ProductVersion", "3.12.1694"
         END
     END
     BLOCK "VarFileInfo"