don't try to calculate queryid from dynamic empty query #176

Author: okbob

expected/README

@@ -2,4 +2,4 @@ plpgsql_check_passive.out			PostgreSQL 14, 15, 16
 plpgsql_check_passive_1.out			PostgreSQL 12, 13
 plpgsql_check_active_1.out			PostgreSQL 12, 13
 plpgsql_check_active_2.out			PostgreSQL 14, 15, 16
-plpgsql_check_active.out			PostgreSQL 17
+plpgsql_check_active.out			PostgreSQL 17, 18

expected/plpgsql_check_active.out

@@ -250,6 +250,20 @@ select plpgsql_profiler_remove_fake_queryid_hook();
 
 (1 row)
 
+drop function f1();
+-- don't crash on empty dynamic query
+create or replace function f1()
+returns void as $$
+begin
+  execute '';
+end;
+$$ language plpgsql;
+select f1();
+ f1 
+----
+ 
+(1 row)
+
 drop function f1();
 set plpgsql_check.profiler to off;
 create function f1()

expected/plpgsql_check_active_1.out

@@ -250,6 +250,20 @@ select plpgsql_profiler_remove_fake_queryid_hook();
 
 (1 row)
 
+drop function f1();
+-- don't crash on empty dynamic query
+create or replace function f1()
+returns void as $$
+begin
+  execute '';
+end;
+$$ language plpgsql;
+select f1();
+ f1 
+----
+ 
+(1 row)
+
 drop function f1();
 set plpgsql_check.profiler to off;
 create function f1()

expected/plpgsql_check_active_2.out

@@ -250,6 +250,20 @@ select plpgsql_profiler_remove_fake_queryid_hook();
 
 (1 row)
 
+drop function f1();
+-- don't crash on empty dynamic query
+create or replace function f1()
+returns void as $$
+begin
+  execute '';
+end;
+$$ language plpgsql;
+select f1();
+ f1 
+----
+ 
+(1 row)
+
 drop function f1();
 set plpgsql_check.profiler to off;
 create function f1()

sql/plpgsql_check_active.sql

@@ -125,6 +125,18 @@ select plpgsql_profiler_remove_fake_queryid_hook();
 
 drop function f1();
 
+-- don't crash on empty dynamic query
+create or replace function f1()
+returns void as $$
+begin
+  execute '';
+end;
+$$ language plpgsql;
+
+select f1();
+
+drop function f1();
+
 set plpgsql_check.profiler to off;
 
 create function f1()

src/profiler.c

@@ -1643,6 +1643,15 @@ profiler_get_dyn_queryid(PLpgSQL_execstate *estate, PLpgSQL_expr *expr, query_pa
 	 */
 	parsetree_list = pg_parse_query(query_string);
 
+
+	/* The query can be empty. Returns NOQUERYID is this case. */
+	if (!parsetree_list)
+	{
+		MemoryContextSwitchTo(oldcxt);
+		MemoryContextReset(profiler_queryid_mcxt);
+		return NOQUERYID;
+	}
+
 	/*
 	 * There should not be more than one query, silently ignore rather than
 	 * error out in that case.