Fix boolean expression handling in query document building.

Reported on GitHub through issue #58 by simon-wolf.

FDW-631, Vaibhav Dalvi, reviewed by Jeevan Chalke.

deparse.c

@@ -380,8 +380,7 @@ mongo_append_bool_expr(BoolExpr *node, BSON *child_doc, pipeline_cxt *context)
 			break;
 		case NOT_EXPR:
 			op = "$not";
-			mongo_append_expr(linitial(node->args), child_doc, context);
-			return;
+			break;
 	}
 
 	bsonAppendStartObject(child_doc, psprintf("%d", context->arrayIndex), &expr);

expected/pushdown.out

@@ -847,6 +847,43 @@ SELECT c1, c4 FROM f_test_tbl1
 
 ALTER SERVER mongo_server OPTIONS (SET enable_order_by_pushdown 'true');
 ALTER FOREIGN TABLE f_test_tbl1 OPTIONS (SET enable_order_by_pushdown 'true');
+-- FDW-631: Test pushdown of boolean expression
+EXPLAIN (VERBOSE, COSTS FALSE)
+SELECT name, pass FROM f_test_tbl3 WHERE pass = false ORDER BY name;
+                       QUERY PLAN                       
+--------------------------------------------------------
+ Sort
+   Output: name, pass
+   Sort Key: f_test_tbl3.name
+   ->  Foreign Scan on public.f_test_tbl3
+         Output: name, pass
+         Foreign Namespace: mongo_fdw_regress.test_tbl3
+(6 rows)
+
+SELECT name, pass FROM f_test_tbl3 WHERE pass = false ORDER BY name;
+ name | pass 
+------+------
+ dvd  | f
+(1 row)
+
+EXPLAIN (VERBOSE, COSTS FALSE)
+SELECT name, pass FROM f_test_tbl3 WHERE pass = true ORDER BY name;
+                       QUERY PLAN                       
+--------------------------------------------------------
+ Sort
+   Output: name, pass
+   Sort Key: f_test_tbl3.name
+   ->  Foreign Scan on public.f_test_tbl3
+         Output: name, pass
+         Foreign Namespace: mongo_fdw_regress.test_tbl3
+(6 rows)
+
+SELECT name, pass FROM f_test_tbl3 WHERE pass = true ORDER BY name;
+ name | pass 
+------+------
+ vdd  | t
+(1 row)
+
 -- Cleanup
 DELETE FROM f_mongo_test WHERE a != 0;
 DELETE FROM f_test_tbl2 WHERE c1 IS NULL;

expected/pushdown_1.out

@@ -907,6 +907,45 @@ ALTER SERVER mongo_server OPTIONS (SET enable_order_by_pushdown 'true');
 ERROR:  option "enable_order_by_pushdown" not found
 ALTER FOREIGN TABLE f_test_tbl1 OPTIONS (SET enable_order_by_pushdown 'true');
 ERROR:  option "enable_order_by_pushdown" not found
+-- FDW-631: Test pushdown of boolean expression
+EXPLAIN (VERBOSE, COSTS FALSE)
+SELECT name, pass FROM f_test_tbl3 WHERE pass = false ORDER BY name;
+                       QUERY PLAN                       
+--------------------------------------------------------
+ Sort
+   Output: name, pass
+   Sort Key: f_test_tbl3.name
+   ->  Foreign Scan on public.f_test_tbl3
+         Output: name, pass
+         Filter: (NOT f_test_tbl3.pass)
+         Foreign Namespace: mongo_fdw_regress.test_tbl3
+(7 rows)
+
+SELECT name, pass FROM f_test_tbl3 WHERE pass = false ORDER BY name;
+ name | pass 
+------+------
+ dvd  | f
+(1 row)
+
+EXPLAIN (VERBOSE, COSTS FALSE)
+SELECT name, pass FROM f_test_tbl3 WHERE pass = true ORDER BY name;
+                       QUERY PLAN                       
+--------------------------------------------------------
+ Sort
+   Output: name, pass
+   Sort Key: f_test_tbl3.name
+   ->  Foreign Scan on public.f_test_tbl3
+         Output: name, pass
+         Filter: f_test_tbl3.pass
+         Foreign Namespace: mongo_fdw_regress.test_tbl3
+(7 rows)
+
+SELECT name, pass FROM f_test_tbl3 WHERE pass = true ORDER BY name;
+ name | pass 
+------+------
+ vdd  | t
+(1 row)
+
 -- Cleanup
 DELETE FROM f_mongo_test WHERE a != 0;
 DELETE FROM f_test_tbl2 WHERE c1 IS NULL;

sql/pushdown.sql

@@ -357,6 +357,14 @@ SELECT c1, c4 FROM f_test_tbl1
 ALTER SERVER mongo_server OPTIONS (SET enable_order_by_pushdown 'true');
 ALTER FOREIGN TABLE f_test_tbl1 OPTIONS (SET enable_order_by_pushdown 'true');
 
+-- FDW-631: Test pushdown of boolean expression
+EXPLAIN (VERBOSE, COSTS FALSE)
+SELECT name, pass FROM f_test_tbl3 WHERE pass = false ORDER BY name;
+SELECT name, pass FROM f_test_tbl3 WHERE pass = false ORDER BY name;
+EXPLAIN (VERBOSE, COSTS FALSE)
+SELECT name, pass FROM f_test_tbl3 WHERE pass = true ORDER BY name;
+SELECT name, pass FROM f_test_tbl3 WHERE pass = true ORDER BY name;
+
 -- Cleanup
 DELETE FROM f_mongo_test WHERE a != 0;
 DELETE FROM f_test_tbl2 WHERE c1 IS NULL;