string returned by function plpgsql_check_get_const_string should not be released, because the the const string can be used more times

Author: okbob

expected/plpgsql_check_active.out

@@ -9544,3 +9544,28 @@ select * from plpgsql_check_function('test_proc_composite');
 drop function test_proc_composite;
 drop procedure proc_composite;
 drop type ct;
+create or replace function double_usage_of_const_str()
+returns void
+as $$
+declare
+  p_id_arr integer[];
+  r_id integer;
+begin
+  p_id_arr := '{1,2,3}'::integer[];
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+  --the following loop causes an error
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+end;
+$$ language plpgsql;
+-- should not to raise false alarm #195
+select * from plpgsql_check_function('double_usage_of_const_str');
+ plpgsql_check_function 
+------------------------
+(0 rows)
+

expected/plpgsql_check_active_2.out

@@ -9543,3 +9543,28 @@ select * from plpgsql_check_function('test_proc_composite');
 drop function test_proc_composite;
 drop procedure proc_composite;
 drop type ct;
+create or replace function double_usage_of_const_str()
+returns void
+as $$
+declare
+  p_id_arr integer[];
+  r_id integer;
+begin
+  p_id_arr := '{1,2,3}'::integer[];
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+  --the following loop causes an error
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+end;
+$$ language plpgsql;
+-- should not to raise false alarm #195
+select * from plpgsql_check_function('double_usage_of_const_str');
+ plpgsql_check_function 
+------------------------
+(0 rows)
+

expected/plpgsql_check_active_3.out

@@ -9544,3 +9544,28 @@ select * from plpgsql_check_function('test_proc_composite');
 drop function test_proc_composite;
 drop procedure proc_composite;
 drop type ct;
+create or replace function double_usage_of_const_str()
+returns void
+as $$
+declare
+  p_id_arr integer[];
+  r_id integer;
+begin
+  p_id_arr := '{1,2,3}'::integer[];
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+  --the following loop causes an error
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+end;
+$$ language plpgsql;
+-- should not to raise false alarm #195
+select * from plpgsql_check_function('double_usage_of_const_str');
+ plpgsql_check_function 
+------------------------
+(0 rows)
+

expected/plpgsql_check_active_4.out

@@ -9545,3 +9545,28 @@ select * from plpgsql_check_function('test_proc_composite');
 drop function test_proc_composite;
 drop procedure proc_composite;
 drop type ct;
+create or replace function double_usage_of_const_str()
+returns void
+as $$
+declare
+  p_id_arr integer[];
+  r_id integer;
+begin
+  p_id_arr := '{1,2,3}'::integer[];
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+  --the following loop causes an error
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+end;
+$$ language plpgsql;
+-- should not to raise false alarm #195
+select * from plpgsql_check_function('double_usage_of_const_str');
+ plpgsql_check_function 
+------------------------
+(0 rows)
+

sql/plpgsql_check_active.sql

@@ -5690,3 +5690,26 @@ select * from plpgsql_check_function('test_proc_composite');
 drop function test_proc_composite;
 drop procedure proc_composite;
 drop type ct;
+
+create or replace function double_usage_of_const_str()
+returns void
+as $$
+declare
+  p_id_arr integer[];
+  r_id integer;
+begin
+  p_id_arr := '{1,2,3}'::integer[];
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+  --the following loop causes an error
+  foreach r_id in array p_id_arr
+  loop
+    raise notice 'id: %', r_id;
+  end loop;
+end;
+$$ language plpgsql;
+
+-- should not to raise false alarm #195
+select * from plpgsql_check_function('double_usage_of_const_str');

src/check_expr.c

@@ -1299,8 +1299,6 @@ plpgsql_check_expr_as_rvalue(PLpgSQL_checkstate *cstate, PLpgSQL_expr *expr,
 
 					getTypeInputInfo(typeid, &infunc, &intypeioparam);
 					(void) OidInputFunctionCall(infunc, str, intypeioparam, -1);
-
-					pfree(str);
 				}
 			}