[PATCH 1/1] wusa: Split cabinet path before calling FDICopy. Wine's wusa currently passes the full cabinet path as the `pszCabinet` argument to `FDICopy()` and passes `NULL` as `pszCabPath`.

[David Carrasco Flores]

From: David Carrasco Flores <[e-mail]>

This works with Wine's builtin cabinet implementation, but it does not
match the documented FDICopy parameter usage. `FDICopy()` expects
`pszCabinet` to contain only the cabinet file name, while `pszCabPath`
contains the directory path. Wine's own FDICopy API documentation follows
that convention, describing `pszCabinet` as the cabinet filename and
`pszCabPath` as the cabinet file path.

Microsoft's FDI documentation is more explicit: `pszCabinet` is the
cabinet file name excluding path information, and `pszCabPath` is the
cabinet path excluding the file name. The full cabinet path is then
constructed internally by appending `pszCabinet` to `pszCabPath`.

`pszCabPath` is an input `LPSTR` parameter and is not documented as
optional. Passing `NULL` is therefore outside the documented API behavior,
even though Wine's builtin cabinet.dll currently tolerates it. Native
cabinet.dll crashes in this context.

These changes are based on the existing path-splitting pattern used by
`SetupIterateCabinetA()` in `dlls/setupapi/setupcab.c`, as well as the FDI
resource-handling pattern used by `extract_cabinet()` in `dlls/msi/media.c`:

- resolve the input path with `GetFullPathNameA()`;
- split the result into `pszCabPath` and `pszCabinet`;
- pass both values separately to `FDICopy()`;
- release allocated memory on failure paths;
- destroy the FDI context after `FDICopy()`, regardless of whether extraction succeeds.

This improves compatibility with native cabinet.dll, which does not tolerate
passing `NULL` for `pszCabPath` in this context.

After applying this patch both native (from VistaSP1 and Win7SP1) and built-in cabinet.dll allow the graceful execution of wusa.exe
---
 programs/wusa/main.c | 51 ++++++++++++++++++++++++++++++++++++++++----
 1 file changed, 47 insertions(+), 4 deletions(-)

diff --git a/programs/wusa/main.c b/programs/wusa/main.c
index ef7302847cc..20b0a21b540 100644
--- a/programs/wusa/main.c
+++ b/programs/wusa/main.c
@@ -246,18 +246,61 @@ static INT_PTR CDECL cabinet_notify(FDINOTIFICATIONTYPE fdint, PFDINOTIFICATION
 static BOOL extract_cabinet(const WCHAR *filename, const WCHAR *destination)
 {
     char *filenameA = NULL;
+    CHAR pszCabinet[MAX_PATH], pszCabPath[MAX_PATH], *filepart = NULL;
+    DWORD fpnsize;
     BOOL ret = FALSE;
     HFDI hfdi;
     ERF erf;
 
+    if (!(filenameA = strdupWtoA(filename)))
+    {
+        SetLastError(ERROR_INVALID_PARAMETER);
+        return FALSE;
+    }
+    
+    if (strlen(filenameA) >= MAX_PATH)
+    {
+        SetLastError(ERROR_BAD_PATHNAME);
+        free(filenameA);
+        return FALSE;
+    }
+    
+    fpnsize = GetFullPathNameA(filenameA, MAX_PATH, pszCabPath, &filepart);
+    
+    if (!fpnsize || fpnsize > MAX_PATH)
+    {
+        SetLastError(ERROR_BAD_PATHNAME);
+        free(filenameA);
+        return FALSE;
+    }
+
+    if (filepart)
+    {
+        strcpy(pszCabinet, filepart);
+        *filepart = '\0';
+    }
+    else
+    {
+        strcpy(pszCabinet, filenameA);
+        pszCabPath[0] = '\0';
+    }
+
+    free(filenameA);
+
+    TRACE("path: %s, cabfile: %s\n", debugstr_a(pszCabPath), debugstr_a(pszCabinet));
+
     hfdi = FDICreate(cabinet_alloc, cabinet_free, cabinet_open, cabinet_read,
                      cabinet_write, cabinet_close, cabinet_seek, 0, &erf);
-    if (!hfdi) return FALSE;
+    if (!hfdi)
+    {
+        ERR("FDICreate failed\n");
+        return FALSE;
+    }
 
-    if ((filenameA = strdupWtoA(filename)))
+    ret = FDICopy(hfdi, pszCabinet, pszCabPath, 0, cabinet_notify, NULL, (void *)destination);
+    if (!ret)
     {
-        ret = FDICopy(hfdi, filenameA, NULL, 0, cabinet_notify, NULL, (void *)destination);
-        free(filenameA);
+        ERR("FDICopy failed\n");
     }
 
     FDIDestroy(hfdi);
-- 
GitLab

https://gitlab.winehq.org/wine/wine/-/merge_requests/10760