[PATCH v3 2/3] kernel32: Add forward slash/relative path handling to GetVolumePathNameW.

[Mark White]

Fixes https://bugs.winehq.org/show_bug.cgi?id=42446

GetVolumePathNameW is causing some incompatibity problems with some Windows
applications such as Native Instruments "Native Access" because of an
inability to handle path names containing forward slash's whereas the
Windows GetVolumePathName's behaviour handles path names with both
forward and back slash's.
This v2 patch also includes GetVolumePathNameW relative path handling.

Tested on Debian Stretch and Windows Vista

Signed-off-by: Mark White <markau0 at lycos.com>
---
 dlls/kernel32/volume.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/dlls/kernel32/volume.c b/dlls/kernel32/volume.c
index ac887b2f3f..c5a38e44a8 100644
--- a/dlls/kernel32/volume.c
+++ b/dlls/kernel32/volume.c
@@ -1670,7 +1670,7 @@ BOOL WINAPI GetVolumePathNameW(LPCWSTR filename, LPWSTR volumepathname, DWORD bu
     WCHAR fallbackpathW[] = { 'C',':','\\',0 };
     NTSTATUS status = STATUS_SUCCESS;
     WCHAR *volumenameW = NULL, *c;
-    WCHAR *fwdslash;
+    WCHAR bufferW[MAX_PATH], *lastpartW = NULL;
     int pos, last_pos, stop_pos;
     UNICODE_STRING nt_name;
     ANSI_STRING unix_name;
@@ -1693,9 +1693,8 @@ BOOL WINAPI GetVolumePathNameW(LPCWSTR filename, LPWSTR volumepathname, DWORD bu
         SetLastError( ERROR_NOT_ENOUGH_MEMORY );
         return FALSE;
     }
-    strcpyW( volumenameW, filename );
-    /* forward slash backslash replace */
-    for (fwdslash = volumenameW; *fwdslash; fwdslash++) if (*fwdslash == '/') *fwdslash = '\\';
+    GetFullPathNameW(filename, MAX_PATH, bufferW, &lastpartW);
+    strcpyW( volumenameW, bufferW );
     stop_pos = 0;
     /* stop searching slashes early for NT-type and nearly NT-type paths */
     if (strncmpW(ntprefixW, filename, strlenW(ntprefixW)) == 0)
-- 
2.11.0