Drop support for Python 2.3

There is no specific reason for this right now, but keeping support for
old Python versions around indefinitely increases the maintenance
burden.  The oldest supported Python version is now Python 2.4, which is
still shipped in RHEL/CentOS 5 by default.

In configure, add a check for the required Python version and give a
friendly error message for an old version, instead of relying on an
obscure build error later on.

3 files changed, 14 insertions, 28 deletions

diff --git a/src/pl/plpython/expected/plpython_ereport.out b/src/pl/plpython/expected/plpython_ereport.out
index 13bd0ab3352..1dafd94c721 100644
--- a/src/pl/plpython/expected/plpython_ereport.out
+++ b/src/pl/plpython/expected/plpython_ereport.out
@@ -94,26 +94,22 @@ kwargs = {
     "column_name": _column_name, "datatype_name": _datatype_name,
     "constraint_name": _constraint_name
 }
-# ignore None values - should work on Python2.3
-dict = {}
-for k in kwargs:
-    if kwargs[k] is not None:
-        dict[k] = kwargs[k]
-plpy.error(**dict)
+# ignore None values
+plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 $$ LANGUAGE plpythonu;
 SELECT raise_exception('hello', 'world');
 ERROR:  plpy.Error: hello
 DETAIL:  world
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 SELECT raise_exception('message text', 'detail text', _sqlstate => 'YY333');
 ERROR:  plpy.Error: message text
 DETAIL:  detail text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 SELECT raise_exception(_message => 'message text',
                        _detail => 'detail text',
@@ -128,8 +124,8 @@ ERROR:  plpy.Error: message text
 DETAIL:  detail text
 HINT:  hint text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 SELECT raise_exception(_message => 'message text',
                        _hint => 'hint text',
@@ -139,8 +135,8 @@ SELECT raise_exception(_message => 'message text',
 ERROR:  plpy.Error: message text
 HINT:  hint text
 CONTEXT:  Traceback (most recent call last):
-  PL/Python function "raise_exception", line 13, in <module>
-    plpy.error(**dict)
+  PL/Python function "raise_exception", line 9, in <module>
+    plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 PL/Python function "raise_exception"
 DO $$
 DECLARE
diff --git a/src/pl/plpython/plpy_typeio.c b/src/pl/plpython/plpy_typeio.c
index b9c6d64baaf..06743e46ed5 100644
--- a/src/pl/plpython/plpy_typeio.c
+++ b/src/pl/plpython/plpy_typeio.c
@@ -521,15 +521,9 @@ PLy_input_datum_func2(PLyDatumToOb *arg, MemoryContext arg_mcxt, Oid typeOid, He
 static PyObject *
 PLyBool_FromBool(PLyDatumToOb *arg, Datum d)
 {
-	/*
-	 * We would like to use Py_RETURN_TRUE and Py_RETURN_FALSE here for
-	 * generating SQL from trigger functions, but those are only supported in
-	 * Python >= 2.4, and we support older versions.
-	 * http://docs.python.org/api/boolObjects.html
-	 */
 	if (DatumGetBool(d))
-		return PyBool_FromLong(1);
-	return PyBool_FromLong(0);
+		Py_RETURN_TRUE;
+	Py_RETURN_FALSE;
 }
 
 static PyObject *
diff --git a/src/pl/plpython/sql/plpython_ereport.sql b/src/pl/plpython/sql/plpython_ereport.sql
index 2612e933876..889293d33c9 100644
--- a/src/pl/plpython/sql/plpython_ereport.sql
+++ b/src/pl/plpython/sql/plpython_ereport.sql
@@ -55,12 +55,8 @@ kwargs = {
     "column_name": _column_name, "datatype_name": _datatype_name,
     "constraint_name": _constraint_name
 }
-# ignore None values - should work on Python2.3
-dict = {}
-for k in kwargs:
-    if kwargs[k] is not None:
-        dict[k] = kwargs[k]
-plpy.error(**dict)
+# ignore None values
+plpy.error(**dict((k, v) for k, v in iter(kwargs.items()) if v))
 $$ LANGUAGE plpythonu;
 
 SELECT raise_exception('hello', 'world');