Invalid read of size 1 in message.pyx

[jameshilliard]

This is probably not the cause of the crash in #42 but when running in valgrind I got this warning.

==3908== Invalid read of size 1
==3908==    at 0x878C056: __pyx_f_5adbus_5sdbus_7Message_read (sdbus.c:8925)
==3908==    by 0x878F2AC: __pyx_f_5adbus_5sdbus_7Message__read_variant (sdbus.c:8274)
==3908==    by 0x878C296: __pyx_f_5adbus_5sdbus_7Message_read (sdbus.c:8994)
==3908==    by 0x8768590: __pyx_f_5adbus_5sdbus_7Message__read_dict (sdbus.c:8747)
==3908==    by 0x878C488: __pyx_f_5adbus_5sdbus_7Message_read (sdbus.c:9038)
==3908==    by 0x8771AE9: __pyx_f_5adbus_5sdbus_7Message__read_array (sdbus.c:7995)
==3908==    by 0x878C1A5: __pyx_f_5adbus_5sdbus_7Message_read (sdbus.c:8972)
==3908==    by 0x877FF0B: __pyx_f_5adbus_5sdbus_call_callback (sdbus.c:21941)
==3908==    by 0x87EA815: process_reply (sd-bus.c:2504)
==3908==    by 0x87F03C4: process_message (sd-bus.c:2683)
==3908==    by 0x87F0580: process_running (sd-bus.c:2745)
==3908==    by 0x87F088E: bus_process_internal (sd-bus.c:2963)
==3908==  Address 0x6575695 is 0 bytes after a block of size 5 alloc'd
==3908==    at 0x4835790: malloc (vg_replace_malloc.c:299)
==3908==    by 0x4D29439: strdup (strdup.c:42)
==3908==    by 0x87D7569: sd_bus_message_enter_container (bus-message.c:4034)
==3908==    by 0x878F27A: __pyx_f_5adbus_5sdbus_7Message__read_variant (sdbus.c:8223)
==3908==    by 0x878C296: __pyx_f_5adbus_5sdbus_7Message_read (sdbus.c:8994)
==3908==    by 0x8768590: __pyx_f_5adbus_5sdbus_7Message__read_dict (sdbus.c:8747)
==3908==    by 0x878C488: __pyx_f_5adbus_5sdbus_7Message_read (sdbus.c:9038)
==3908==    by 0x8771AE9: __pyx_f_5adbus_5sdbus_7Message__read_array (sdbus.c:7995)
==3908==    by 0x878C1A5: __pyx_f_5adbus_5sdbus_7Message_read (sdbus.c:8972)
==3908==    by 0x877FF0B: __pyx_f_5adbus_5sdbus_call_callback (sdbus.c:21941)
==3908==    by 0x87EA815: process_reply (sd-bus.c:2504)
==3908==    by 0x87F03C4: process_message (sd-bus.c:2683)
==3908== 

This(sdbus.c:8925) seems to be specific line doing the invalid read. For reference this is my generated sdbus.c.

[jameshilliard]

Possible fix in #46.