kernel32: Set last error to ERROR_FILE_NOT_FOUND if lpAppName is NULL.

dlls/kernel32/profile.c

@@ -1446,8 +1446,7 @@ BOOL WINAPI WritePrivateProfileStringW( LPCWSTR section, LPCWSTR entry,
     else if (PROFILE_Open( filename, TRUE ))
     {
         if (!section) {
-            FIXME("(NULL?,%s,%s,%s)?\n",
-                  debugstr_w(entry), debugstr_w(string), debugstr_w(filename));
+            SetLastError(ERROR_FILE_NOT_FOUND);
         } else {
             ret = PROFILE_SetString( section, entry, string, FALSE);
             PROFILE_FlushFile();

dlls/kernel32/tests/profile.c

@@ -855,11 +855,8 @@ static void test_WritePrivateProfileString(void)
     SetLastError(0xdeadbeef);
     ret = WritePrivateProfileStringA(NULL, "key", "string", path);
     ok(ret == FALSE, "Expected FALSE, got %d\n", ret);
-    todo_wine
-    {
     ok(GetLastError() == ERROR_FILE_NOT_FOUND,
        "Expected ERROR_FILE_NOT_FOUND, got %d\n", GetLastError());
-    }
     ok(check_file_data(path, data), "File doesn't match\n");
     DeleteFileA(path);