[libvirt] python module set-up ignores virInitialize failure

[Jim Meyering]

Daniel P. Berrange wrote:

> On Tue, May 18, 2010 at 11:43:30AM +0100, Daniel P. Berrange wrote:
>> On Tue, May 18, 2010 at 12:32:13PM +0200, Jim Meyering wrote:
>> > I've just fixed code in a test that ignored virInitialize failure.
>> > Looking at all uses, I saw one other: in python/libvirt-override.c,
>> > where the initialization function ignores virInitialize failure:
>> >
>> >   void
>> >   #ifndef __CYGWIN__
>> >   initlibvirtmod
>> >   #else
>> >   initcygvirtmod
>> >   #endif
>> >     (void)
>> >   {
>> >       static int initialized = 0;
>> >
>> >       if (initialized != 0)
>> >           return;
>> >
>> >       virInitialize();
>> >
>> >       /* initialize the python extension module */
>> >       Py_InitModule((char *)
>> >   #ifndef __CYGWIN__
>> >                     "libvirtmod"
>> >   #else
>> >                     "cygvirtmod"
>> >   #endif
>> >                     , libvirtMethods);
>> >
>> >       initialized = 1;
>> >   }
>> >
>> > Unfortunately, this function is public, so we can't change its signature.
>>
>> More specifically, the signature is defined by Python's loadable
>> module interface so we're not at liberty to redeclare that.
>>
>> > Any suggestions?
>>
>> abort()
>
> Actually I've got another idea. Make the Py_InitModule() call conditional
> on virInitialize() suceeding. That way if virInitialize() fails, none of
> the libvirt APIs will get bound to the python layer, preventing their
> use

Either works for me:

>From 7dbf938ab10657a94702cd766afa336fc68d8c80 Mon Sep 17 00:00:00 2001
From: Jim Meyering <meyering at redhat.com>
Date: Tue, 18 May 2010 13:46:27 +0200
Subject: [PATCH] python: don't ignore virInitialize failure in module initialization

* python/libvirt-override.c (initlibvirtmod): Upon virInitialize
failure, skip the Py_InitModule call.
---
 python/libvirt-override.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/python/libvirt-override.c b/python/libvirt-override.c
index b97445b..c9721f7 100644
--- a/python/libvirt-override.c
+++ b/python/libvirt-override.c
@@ -3534,25 +3534,26 @@ void
 #ifndef __CYGWIN__
 initlibvirtmod
 #else
 initcygvirtmod
 #endif
   (void)
 {
     static int initialized = 0;

     if (initialized != 0)
         return;

-    virInitialize();
+    if (virInitialize() < 0)
+        return;

     /* initialize the python extension module */
     Py_InitModule((char *)
 #ifndef __CYGWIN__
                   "libvirtmod"
 #else
                   "cygvirtmod"
 #endif
                   , libvirtMethods);

     initialized = 1;
 }
--
1.7.1.250.g7d1e8