Preserve SQLSTATE when an SPI error is propagated through PL/python

exception handler. This was a regression in 9.1, when the capability
to catch specific SPI errors was added, so backpatch to 9.1.

Mika Eloranta, with some editing by Jan Urbański.

1 files changed, 22 insertions, 0 deletions

diff --git a/src/pl/plpython/expected/plpython_error.out b/src/pl/plpython/expected/plpython_error.out
index dbf19fda9b9..bab07fbeb24 100644
--- a/src/pl/plpython/expected/plpython_error.out
+++ b/src/pl/plpython/expected/plpython_error.out
@@ -351,6 +351,28 @@ CONTEXT:  PL/Python function "specific_exception"
  
 (1 row)
 
+/* SPI errors in PL/Python functions should preserve the SQLSTATE value
+ */
+CREATE FUNCTION python_unique_violation() RETURNS void AS $$
+plpy.execute("insert into specific values (1)")
+plpy.execute("insert into specific values (1)")
+$$ LANGUAGE plpythonu;
+CREATE FUNCTION catch_python_unique_violation() RETURNS text AS $$
+begin
+    begin
+        perform python_unique_violation();
+    exception when unique_violation then
+        return 'ok';
+    end;
+    return 'not reached';
+end;
+$$ language plpgsql;
+SELECT catch_python_unique_violation();
+ catch_python_unique_violation 
+-------------------------------
+ ok
+(1 row)
+
 /* manually starting subtransactions - a bad idea
  */
 CREATE FUNCTION manual_subxact() RETURNS void AS $$