Prevent the flattening or where-term push-down optimizations from obscuring

misuses of SQL row values that can lead to crashes or assert() failures.

FossilOrigin-Name: 433d16ff3adfede3be53d5b0e0512f37e225591b

test/rowvalue.test

@@ -291,6 +291,31 @@ do_execsql_test 14.6 {
   SELECT 1 FROM t12 WHERE (1,x) BETWEEN (1,1) AND (3,3)
 } {1 1}
 
+#-------------------------------------------------------------------------
+# Test that errors are not concealed by the SELECT flattening or
+# WHERE-clause push-down optimizations.
+do_execsql_test 14.1 {
+  CREATE TABLE x1(a PRIMARY KEY, b);
+  CREATE TABLE x2(a INTEGER PRIMARY KEY, b);
+}
+
+foreach {tn n sql} {
+  1 0 "SELECT * FROM (SELECT (1, 1) AS c FROM x1) WHERE c=1"
+  2 2 "SELECT * FROM (SELECT 1 AS x, (SELECT 8,9) AS y) WHERE y<1"
+  3 3 "SELECT * FROM (SELECT 1 AS x, (SELECT 8,9,10) AS y) WHERE y<1"
+  4 0 "SELECT * FROM (SELECT (a, b) AS c FROM x1), x2 WHERE c=a"
+  5 0 "SELECT * FROM (SELECT a AS c, (1, 2, 3) FROM x1), x2 WHERE c=a"
+  6 0 "SELECT * FROM (SELECT 1 AS c, (1, 2, 3) FROM x1) WHERE c=1"
+} {
+  if {$n==0} {
+    set err "row value misused"
+  } else {
+    set err "sub-select returns $n columns - expected 1"
+  }
+  do_catchsql_test 14.2.$tn $sql [list 1 $err]
+}
+
+
 finish_test