ntdll: Use the loadFrom directory to load dlls from the activation context.

dlls/ntdll/loader.c

@@ -2432,6 +2432,44 @@ failed:
 
 
 /***********************************************************************
+ *	build_dlldata_path
+ *
+ * Helper for find_actctx_dll.
+ */
+static NTSTATUS build_dlldata_path( LPCWSTR libname, ACTCTX_SECTION_KEYED_DATA *data, LPWSTR *fullname )
+{
+    struct dllredirect_data *dlldata = data->lpData;
+    char *base = data->lpSectionBase;
+    SIZE_T total = dlldata->total_len + (wcslen(libname) + 1) * sizeof(WCHAR);
+    WCHAR *p, *buffer;
+    NTSTATUS status = STATUS_SUCCESS;
+    ULONG i;
+
+    if (!(p = buffer = RtlAllocateHeap( GetProcessHeap(), 0, total ))) return STATUS_NO_MEMORY;
+    for (i = 0; i < dlldata->paths_count; i++)
+    {
+        memcpy( p, base + dlldata->paths[i].offset, dlldata->paths[i].len );
+        p += dlldata->paths[i].len / sizeof(WCHAR);
+    }
+    wcscpy( p, libname );
+
+    if (dlldata->flags & DLL_REDIRECT_PATH_EXPAND)
+    {
+        RtlExpandEnvironmentStrings( NULL, buffer, wcslen(buffer), NULL, 0, &total );
+        if ((*fullname = RtlAllocateHeap( GetProcessHeap(), 0, total * sizeof(WCHAR) )))
+            RtlExpandEnvironmentStrings( NULL, buffer, wcslen(buffer), *fullname, total, NULL );
+        else
+            status = STATUS_NO_MEMORY;
+
+        RtlFreeHeap( GetProcessHeap(), 0, buffer );
+    }
+    else *fullname = buffer;
+
+    return status;
+}
+
+
+/***********************************************************************
  *	find_actctx_dll
  *
  * Find the full path (if any) of the dll from the activation context.
@@ -2440,8 +2478,9 @@ static NTSTATUS find_actctx_dll( LPCWSTR libname, LPWSTR *fullname )
 {
     static const WCHAR winsxsW[] = {'\\','w','i','n','s','x','s','\\'};
 
-    ACTIVATION_CONTEXT_ASSEMBLY_DETAILED_INFORMATION *info;
+    ACTIVATION_CONTEXT_ASSEMBLY_DETAILED_INFORMATION *info = NULL;
     ACTCTX_SECTION_KEYED_DATA data;
+    struct dllredirect_data *dlldata;
     UNICODE_STRING nameW;
     NTSTATUS status;
     SIZE_T needed, size = 1024;
@@ -2454,6 +2493,18 @@ static NTSTATUS find_actctx_dll( LPCWSTR libname, LPWSTR *fullname )
                                                     &nameW, &data );
     if (status != STATUS_SUCCESS) return status;
 
+    if (data.ulLength < offsetof( struct dllredirect_data, paths[0] ))
+    {
+        status = STATUS_SXS_KEY_NOT_FOUND;
+        goto done;
+    }
+    dlldata = data.lpData;
+    if (!(dlldata->flags & DLL_REDIRECT_PATH_OMITS_ASSEMBLY_ROOT))
+    {
+        status = build_dlldata_path( libname, &data, fullname );
+        goto done;
+    }
+
     for (;;)
     {
         if (!(info = RtlAllocateHeap( GetProcessHeap(), 0, size )))