msi: Validate the parameters of MsiOpenPackage.

dlls/msi/package.c

@@ -932,9 +932,15 @@ UINT WINAPI MsiOpenPackageExW(LPCWSTR szPackage, DWORD dwOptions, MSIHANDLE *phP
 
     TRACE("%s %08x %p\n", debugstr_w(szPackage), dwOptions, phPackage );
 
-    if( szPackage == NULL )
+    if( !szPackage || !phPackage )
         return ERROR_INVALID_PARAMETER;
 
+    if ( !*szPackage )
+    {
+        FIXME("Should create an empty database and package.");
+        return ERROR_FUNCTION_FAILED;
+    }
+
     if( dwOptions )
         FIXME("dwOptions %08x not supported\n", dwOptions);
 

dlls/msi/tests/package.c

@@ -2056,10 +2056,7 @@ static void test_msipackage(void)
 
     /* NULL hProduct */
     r = MsiOpenPackage(msifile, NULL);
-    todo_wine
-    {
-        ok(r == ERROR_INVALID_PARAMETER, "Expected ERROR_INVALID_PARAMETER, got %d\n", r);
-    }
+    ok(r == ERROR_INVALID_PARAMETER, "Expected ERROR_INVALID_PARAMETER, got %d\n", r);
 
     name[0]='#';
     name[1]=0;