RE: psql - add SHOW_ALL_RESULTS option

Hi Fabien, 

I review your patch. 

> Add a few tests for the new feature.
+++ b/src/test/regress/expected/psql.out
@@ -4729,3 +4729,46 @@ drop schema testpart;
 set search_path to default;
 set role to default;
 drop role testrole_partitioning;
+-- 
There is space (+--' '). Please delete it. It is cause of regression test failed.

> IMHO this new setting should be on by default: few people know about \; so
> it would not change anything for most, and I do not see why those who use
> it would not be interested by the results of all the queries they asked for.
I agree with your opinion.

I test some query combination case. And I found when warning happen, the message is printed in head of results. I think it is not clear in which query the warning occurred.
How about print warning message before the query that warning occurred?

For example,
-- devide by ';'
postgres=# BEGIN; BEGIN; SELECT 1 AS one; COMMIT; BEGIN; BEGIN; SELECT 1 AS one; COMMIT;
BEGIN
psql: WARNING:  there is already a transaction in progress
BEGIN
 one 
-----
   1
(1 row)

COMMIT
BEGIN
psql: WARNING:  there is already a transaction in progress
BEGIN
 one 
-----
   1
(1 row)

COMMIT


-- devide by '\;' and set SHOW_RESULT_ALL on
postgres=# \set SHOW_ALL_RESULTS on
postgres=# BEGIN\; BEGIN\; SELECT 1 AS one\; COMMIT\; BEGIN\; BEGIN\; SELECT 1 AS one\; COMMIT;
psql: WARNING:  there is already a transaction in progress
BEGIN
BEGIN
 one 
-----
   1
(1 row)

psql: WARNING:  there is already a transaction in progress
COMMIT
BEGIN
BEGIN
 one 
-----
   1
(1 row)

COMMIT

I will check the code soon.

Regards, 
Aya Iwata