Fix the xBestIndex method of the pragma virtual table so that it correctly

gives a higher cost to plans where the schema hidden parameter is
unconstrained.  Fix for the problem reported by
[forum:/forumpost/85b6a8b6705fb77a|forum post 85b6a8b6705fb77a].

FossilOrigin-Name: bc516ff5202ee6e9834266bf755fe26e30ac557dcc7975ca7a06dfe33874fcd2

test/pragma4.test

@@ -264,5 +264,17 @@ do_execsql_test 5.0 {
   0 a {} 0 'abc' 0 1 b {} 0 -1 0 2 c {} 0 +4.0 0
 }
 
+# 2024-03-24 https://sqlite.org/forum/forumpost/85b6a8b6705fb77a
+#
+reset_db
+do_execsql_test 6.0 {
+  CREATE TABLE t1(a INT PRIMARY KEY, b INT);
+  CREATE TABLE t2(c INT PRIMARY KEY, d INT REFERENCES t1);
+  SELECT t.name, f."table", f."from", i.name, i.pk
+    FROM pragma_table_list() AS t
+         JOIN pragma_foreign_key_list(t.name, t.schema) AS f
+         JOIN pragma_table_info(f."table", t.schema) AS i
+   WHERE i.pk;
+} {t2 t1 d a 1}
 
 finish_test