Fix aboriginal mistake in plpython's set-returning-function support.

We must stay in the function's SPI context until done calling the iterator
that returns the set result.  Otherwise, any attempt to invoke SPI features
in the python code called by the iterator will malfunction.  Diagnosis and
patch by Jan Urbanski, per bug report from Jean-Baptiste Quenot.

Back-patch to 8.2; there was no support for SRFs in previous versions of
plpython.

1 files changed, 9 insertions, 0 deletions

diff --git a/src/pl/plpython/sql/plpython_function.sql b/src/pl/plpython/sql/plpython_function.sql
index a1544f3c422..0872f1a3091 100644
--- a/src/pl/plpython/sql/plpython_function.sql
+++ b/src/pl/plpython/sql/plpython_function.sql
@@ -448,6 +448,15 @@ class producer:
 return producer(count, content)
 $$ LANGUAGE plpythonu;
 
+CREATE FUNCTION test_setof_spi_in_iterator() RETURNS SETOF text AS
+$$
+    for s in ('Hello', 'Brave', 'New', 'World'):
+        plpy.execute('select 1')
+        yield s
+        plpy.execute('select 2')
+$$
+LANGUAGE plpythonu;
+
 
 --
 -- Test returning tuples