Carbon segfault with 1.9

[prymitive]

Am I doing something wrong? Fresh checkout on 2 different machines give me:

/u$ ./uwsgi --http :8080 --wsgi-file tests/staticfile.py --carbon xxx
*** Starting uWSGI 1.9 (64bit) on [Wed Mar 20 20:32:46 2013] ***
compiled with version: 4.6.3 on 20 March 2013 20:32:36
os: Linux-3.2.0-38-generic #61-Ubuntu SMP Tue Feb 19 12:18:21 UTC 2013
[...]
[carbon] added server xxx
[carbon] carbon plugin started, 60s frequency, 3s timeout, max retries 1, retry delay 7s
!!! uWSGI process 1124 got Segmentation Fault !!!
*** backtrace of 1124 ***
./uwsgi(uwsgi_backtrace+0x25) [0x451b95]
./uwsgi(uwsgi_segfault+0x21) [0x451c71]
/lib/x86_64-linux-gnu/libc.so.6(+0x364a0) [0x7f7982a804a0]
/lib/x86_64-linux-gnu/libc.so.6(+0x89101) [0x7f7982ad3101]
./uwsgi(uwsgi_concat2+0x23) [0x44cd83]
./uwsgi(uwsgi_stats_pusher_add+0xa2) [0x437342]
./uwsgi() [0x470715]
./uwsgi(uwsgi_start+0x43f) [0x452cbf]
./uwsgi(main+0x17aa) [0x41be2a]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xed) [0x7f7982a6b76d]
./uwsgi() [0x41bea5]
*** end of backtrace ***

This is caused by uspi->arg = uwsgi_str(arg); on https://github.com/unbit/uwsgi/blob/master/core/stats.c#L386

since arg is passed as NULL, so uwsgi_str(NULL) fails in very ugly way.

This fixes it

diff --git a/core/stats.c b/core/stats.c
index 4cf5ebd..19ac3cf 100644
--- a/core/stats.c
+++ b/core/stats.c
@@ -383,7 +383,9 @@ struct uwsgi_stats_pusher_instance *uwsgi_stats_pusher_add(struct uwsgi_stats_pu

        uspi = uwsgi_calloc(sizeof(struct uwsgi_stats_pusher_instance));
        uspi->pusher = pusher;
-       uspi->arg = uwsgi_str(arg);
+       if (uspi->arg) {
+               uspi->arg = uwsgi_str(arg);
+       }
        uspi->raw = pusher->raw;
        if (old_uspi) {
                old_uspi->next = uspi;

But maybe real bug is elsewhere, maybe arg should be != NULL?
This happens with both 1.9 tag and current master.

[prymitive]

fix was merged with #188, closing