[PATCH v21 0/1] MR10192: Draft: kernelbase: Handle extended length path prefix in GetLongPathNameW

[Vishnunithyasoundhar S (＠svishnunithyasoundhar)]

```
Support the \\?\ prefix by skipping it during path resolution while 
preserving it in the output. Added specific handling for extended 
UNC paths (\\?\UNC\) to mirror standard UNC behavior, ensuring 
these paths are treated as network shares and not local devices.

Some paths that use the extended length path were filtered out as UNC 
paths - but not all of them are UNC. There can be UNC path that use
extended length path but not all extended lenght paths are UNC paths.
```

Signed-off-by: Vishnunithyasoundhar S [e-mail]

--
  v21: fix: extended-file-name support
 
https://gitlab.winehq.org/wine/wine/-/merge_requests/10192

[PATCH v21 1/1] fix: extended-file-name support

[Vishnunithyasoundhar S]

From: Vishnunithyasoundhar S <[e-mail]>

Signed-off-by: Vishnunithyasoundhar S <[e-mail]>
---
 dlls/kernelbase/file.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/dlls/kernelbase/file.c b/dlls/kernelbase/file.c
index c206e2f9cc2..d158b59d57e 100644
--- a/dlls/kernelbase/file.c
+++ b/dlls/kernelbase/file.c
@@ -2117,6 +2117,21 @@ DWORD WINAPI DECLSPEC_HOTPATCH GetLongPathNameW( LPCWSTR shortpath, LPWSTR longp
         return 0;
     }
 
+    /* Handle \\?\ prefix (Extended Length Path) */
+    if (shortpath[0] == '\\' && shortpath[1] == '\\' && shortpath[2] == '?' &&
+        shortpath[3] == '\\') {
+      /* Filter out entended UNC */
+      if (_wcsnicmp(shortpath + 4, L"UNC\\", 4) == 0) {
+        lstrcatW(tmplongpath, L"UNC\\");
+        lp = sp = 8;
+        FIXME("UNC Extended pathname %s\n", debugstr_w(shortpath));
+      }
+      else if (shortpath[4] && shortpath[5] == ':') {
+        tmplongpath[lp++] = shortpath[sp++];
+        tmplongpath[lp++] = shortpath[sp++];
+      }
+    }
+
     if (shortpath[0] == '\\' && shortpath[1] == '\\')
     {
         FIXME( "UNC pathname %s\n", debugstr_w(shortpath) );
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10192