Free SQLSTATE and SQLERRM no earlier than other PL/pgSQL variables.

"RETURN SQLERRM" prompted plpgsql_exec_function() to read from freed
memory.  Back-patch to 9.0 (all supported versions).  Little code ran
between the premature free and the read, so non-assert builds are
unlikely to witness user-visible consequences.

2 files changed, 21 insertions, 1 deletions

diff --git a/src/test/regress/expected/plpgsql.out b/src/test/regress/expected/plpgsql.out
index daf3447915d..2c0b2e5e2b1 100644
--- a/src/test/regress/expected/plpgsql.out
+++ b/src/test/regress/expected/plpgsql.out
@@ -2655,9 +2655,21 @@ NOTICE:  P0001 user exception
  
 (1 row)
 
+create function excpt_test4() returns text as $$
+begin
+	begin perform 1/0;
+	exception when others then return sqlerrm; end;
+end; $$ language plpgsql;
+select excpt_test4();
+   excpt_test4    
+------------------
+ division by zero
+(1 row)
+
 drop function excpt_test1();
 drop function excpt_test2();
 drop function excpt_test3();
+drop function excpt_test4();
 -- parameters of raise stmt can be expressions
 create function raise_exprs() returns void as $$
 declare
diff --git a/src/test/regress/sql/plpgsql.sql b/src/test/regress/sql/plpgsql.sql
index a0840c9dc8d..001138eea28 100644
--- a/src/test/regress/sql/plpgsql.sql
+++ b/src/test/regress/sql/plpgsql.sql
@@ -2246,11 +2246,19 @@ begin
 	    raise notice '% %', sqlstate, sqlerrm;
     end;
 end; $$ language plpgsql;
-
 select excpt_test3();
+
+create function excpt_test4() returns text as $$
+begin
+	begin perform 1/0;
+	exception when others then return sqlerrm; end;
+end; $$ language plpgsql;
+select excpt_test4();
+
 drop function excpt_test1();
 drop function excpt_test2();
 drop function excpt_test3();
+drop function excpt_test4();
 
 -- parameters of raise stmt can be expressions
 create function raise_exprs() returns void as $$