patch 7.4.1843

Problem:    Tests involving Python are flaky.
Solution:   Set the pt_auto field.  Add tests. (Nikolai Pavlov)

src/version.c

@@ -753,6 +753,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1843,
 /**/
     1842,
 /**/