[COMMIT] py_decref: Don't check for NULL before calling Py_DECREF. (was: Re: [patch] Compilation regression with python-2.6)

[Pedro Alves <palves@redhat.com>]

On 05/21/2013 06:32 PM, Tom Tromey wrote:
>>>>>> "Pedro" == Pedro Alves <palves@redhat.com> writes:
> 
> Pedro> If you think this is not good, then I'll just file a PR.
> 
> It is totally fine.  Please check it in.

Thanks.  Done.

---------
Subject: py_decref: Don't check for NULL before calling Py_DECREF.

The only difference between Py_DECREF and Py_XDECREF is that the latter allows passing
in a NULL object, while the former prohibits it.  Given that, it's natural to expect
the same from py_decref vs py_xdecref.

gdb/
2013-05-21  Pedro Alves  <palves@redhat.com>

	* python/py-prettyprint.c (apply_val_pretty_printer): Check
	whether PRINTER is NULL before installing a Py_DECREF cleanup.
	* python/py-utils.c (py_decref): Don't check for NULL before
	calling Py_DECREF.
---
 gdb/python/py-prettyprint.c |    6 +++++-
 gdb/python/py-utils.c       |    3 +--
 2 files changed, 6 insertions(+), 3 deletions(-)

diff --git a/gdb/python/py-prettyprint.c b/gdb/python/py-prettyprint.c
index 8c45cd6..8fa2f42 100644
--- a/gdb/python/py-prettyprint.c
+++ b/gdb/python/py-prettyprint.c
@@ -735,8 +735,12 @@ apply_val_pretty_printer (struct type *type, const gdb_byte *valaddr,
   /* Find the constructor.  */
   printer = find_pretty_printer (val_obj);
   Py_DECREF (val_obj);
+
+  if (printer == NULL)
+    goto done;
+
   make_cleanup_py_decref (printer);
-  if (! printer || printer == Py_None)
+  if (printer == Py_None)
     goto done;

   /* If we are printing a map, we want some special formatting.  */
diff --git a/gdb/python/py-utils.c b/gdb/python/py-utils.c
index 80bacf7..7c7c5ca 100644
--- a/gdb/python/py-utils.c
+++ b/gdb/python/py-utils.c
@@ -31,8 +31,7 @@ py_decref (void *p)
 {
   PyObject *py = p;

-  if (py)
-    Py_DECREF (py);
+  Py_DECREF (py);
 }

 /* Return a new cleanup which will decrement the Python object's