[PATCH v2 0/1] MR8528: ntdll: Remove trailing slashes from the NT names for directories.

[Tim Clem (＠tclem)]

Fixes a regression with af35741d.

---

The EA Games launcher depends on `GetFinalPathNameByHandleW` returning a path *without* a trailing slash for directories, even if the handle was opened with one. After af35741d, we now use the server's notion of the fd path (via `NtQueryObject(ObjectNameInformation)`), which will include a trailing slash if that's how the path was specified when opened.

A quick test on Windows show that `NtQueryObject(ObjectNameInformation)` for file handles returns a `\Device...` path. (This is why I didn't add tests for its behavior.) For directories, `ObjectNameInformation` will only return a trailing slash for the root of a device - e.g. `\Device\HarddiskVolume3` for `C:`, but `\Device\HarddiskVolume3\Windows` for `C:\Windows`.

~~Since our `NtQueryObject(ObjectNameInformation)` already doesn't match native (we return `??` paths), arguably this change should be made in `GetFinalPathNameByHandleW`. It seemed cleaner in the server though, as we immediately know whether a path points to a directory.~~

Now doing this client-side in `get_nt_and_unix_names`, which intercepts paths before they're handed to the server.

--
  v2: ntdll: Remove trailing slashes from the NT names for directories.

https://gitlab.winehq.org/wine/wine/-/merge_requests/8528

[PATCH v2 1/1] ntdll: Remove trailing slashes from the NT names for directories.

[Tim Clem]

From: Tim Clem

Fixes a regression with af35741d.
---
 dlls/kernel32/tests/file.c | 24 ++++++++++++++++++++++++
 dlls/ntdll/unix/file.c     | 22 ++++++++++++++++++++++
 2 files changed, 46 insertions(+)

diff --git a/dlls/kernel32/tests/file.c b/dlls/kernel32/tests/file.c
index 83766dfaaa2..1a5981261a5 100644
--- a/dlls/kernel32/tests/file.c
+++ b/dlls/kernel32/tests/file.c
@@ -5436,6 +5436,30 @@ static void test_GetFinalPathNameByHandleW(void)
        wine_dbgstr_w(nt_path), wine_dbgstr_w(result_path));

CloseHandle(file);
+
+    /* Roots of drives should come back with a trailing slash. */
+    file = CreateFileW(L"C:\", GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
+                       OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0);
+    ok(file != INVALID_HANDLE_VALUE, "CreateFileW error %lu\n", GetLastError());
+    memset(result_path, 0x11, sizeof(result_path));
+    count = pGetFinalPathNameByHandleW(file, result_path, MAX_PATH, FILE_NAME_NORMALIZED | VOLUME_NAME_DOS);
+    lstrcpyW(dos_path, L"\\?\C:\");
+    ok(count == lstrlenW(dos_path), "Expected length %u, got %lu\n", lstrlenW(dos_path), count);
+    ok(lstrcmpiW(dos_path, result_path) == 0, "Expected %s, got %s\n",
+       wine_dbgstr_w(dos_path), wine_dbgstr_w(result_path));
+    CloseHandle(file);
+
+    /* Other directories should not have a trailing slash. */
+    file = CreateFileW(L"C:\windows\", GENERIC_READ, FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, NULL,
+                       OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0);
+    ok(file != INVALID_HANDLE_VALUE, "CreateFileW error %lu\n", GetLastError());
+    memset(result_path, 0x11, sizeof(result_path));
+    count = pGetFinalPathNameByHandleW(file, result_path, MAX_PATH, FILE_NAME_NORMALIZED | VOLUME_NAME_DOS);
+    lstrcpyW(dos_path, L"\\?\C:\windows");
+    ok(count == lstrlenW(dos_path), "Expected length %u, got %lu\n", lstrlenW(dos_path), count);
+    ok(lstrcmpiW(dos_path, result_path) == 0, "Expected %s, got %s\n",
+       wine_dbgstr_w(dos_path), wine_dbgstr_w(result_path));
+    CloseHandle(file);
 }

static void test_SetFileInformationByHandle(void)
diff --git a/dlls/ntdll/unix/file.c b/dlls/ntdll/unix/file.c
index 5bed090a45b..a6c60635e33 100644
--- a/dlls/ntdll/unix/file.c
+++ b/dlls/ntdll/unix/file.c
@@ -4045,8 +4045,30 @@ NTSTATUS get_nt_and_unix_names( OBJECT_ATTRIBUTES *attr, UNICODE_STRING *nt_name
     if (status && status != STATUS_NO_SUCH_FILE)
         TRACE( "%s -> ret %x\n", debugstr_us(orig), status );
     else
+    {
+        /* Trim trailing slashes from anything other than roots of drives. */
+        USHORT nt_len = attr->ObjectName->Length / sizeof(WCHAR);
+        if (nt_len > 7 /* "??\X:" */ && attr->ObjectName->Buffer[nt_len - 1] == '\')
+        {
+            if (nt_name->Buffer)
+            {
+                nt_name->Buffer[nt_len - 1] = 0;
+                nt_name->Length -= sizeof(WCHAR);
+            }
+            else
+            {
+                WCHAR *buffer = malloc( nt_len * sizeof(WCHAR) );
+                if (!buffer) return STATUS_NO_MEMORY;
+                memcpy( buffer, attr->ObjectName->Buffer, (nt_len - 1) * sizeof(WCHAR) );
+                buffer[nt_len - 1] = 0;
+                init_unicode_string( nt_name, buffer );
+                attr->ObjectName = nt_name;
+            }
+        }
+
         TRACE( "%s -> ret %x nt %s unix %s\n", debugstr_us(orig),
                status, debugstr_us(attr->ObjectName), debugstr_a(*unix_name_ret) );
+    }
     return status;
 }

[Tim Clem (＠tclem)]

On Wed Jul  9 16:36:21 2025 +0000, Alexandre Julliard wrote:
> This should most likely be done client-side. In general the server
> doesn't interpret the NT path, it just passes it through.

v2 does this in ntdll. `get_nt_and_unix_names` seemed like the most sensible place to me, but I'm open to suggestions obviously.

[Alexandre Julliard (＠julliard)]

On Wed Jul  9 16:36:21 2025 +0000, Tim Clem wrote:
> v2 does this in ntdll. `get_nt_and_unix_names` seemed like the most
> sensible place to me, but I'm open to suggestions obviously.

You can't assume that you get a drive letter path, there are other possible formats. Also the tests should use NtCreateFile to confirm that this should be done on the kernel side.