I ran telepathy-idle in Valgrind with IDLE_PERSIST=1 IDLE_DEBUG=all. But I forgot to run valgrind with GSLICE=malloc, my bad! So the memory check is not interesting at all... I'll do it again, but for now here's the end of the log, if that can help:

** (telepathy-idle:5611): DEBUG: _parse_and_forward_one: message code 10
** (telepathy-idle:5611): DEBUG: _parse_atom: parsing atom "andreasma!~<email address hidden>" as c
** (telepathy-idle:5611): DEBUG: idle_nickname_is_valid: Validating nickname 'andreasma' with strict mode 0
** (telepathy-idle:5611): DEBUG: _parse_atom: set handle 252
** (telepathy-idle:5611): DEBUG: _parse_atom: parsing atom "PRIVMSG" as I
** (telepathy-idle:5611): DEBUG: _parse_atom: ignored token
** (telepathy-idle:5611): DEBUG: _parse_atom: parsing atom "#libreoffice" as r
** (telepathy-idle:5611): DEBUG: _parse_atom: set handle 3
** (telepathy-idle:5611): DEBUG: _parse_and_forward_one: set string "I get an issue with tabs inside the source code. I have only translated the comments. How can I fix the problem with the tabs?"
** (telepathy-idle:5611): DEBUG: _parse_and_forward_one: succesfully parsed
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_receive_with_flags: queued message 147
** (telepathy-idle:5611): DEBUG: _parse_and_forward_one: message code 11
** (telepathy-idle:5611): DEBUG: _parse_atom: parsing atom "andreasma!~<email address hidden>" as c
** (telepathy-idle:5611): DEBUG: idle_nickname_is_valid: Validating nickname 'andreasma' with strict mode 0
** (telepathy-idle:5611): DEBUG: _parse_atom: set handle 252
** (telepathy-idle:5611): DEBUG: _parse_atom: parsing atom "PRIVMSG" as I
** (telepathy-idle:5611): DEBUG: _parse_atom: ignored token
** (telepathy-idle:5611): DEBUG: _parse_atom: parsing atom "#libreoffice" as c
** (telepathy-idle:5611): DEBUG: idle_nickname_is_valid: Validating nickname '#libreoffice' with strict mode 0
** (telepathy-idle:5611): DEBUG: idle_nickname_is_valid: invalid character 35
** (telepathy-idle:5611): DEBUG: _parse_and_forward_one: failed to parse ":andreasma!~<email address hidden> PRIVMSG #libreoffice :I get an issue with tabs inside the source code. I have only translated the comments. How can I fix the problem with the tabs?"
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 0
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 1
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 2
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 3
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 4
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 5
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 6
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 7
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 8
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 9
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 10
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 11
(telepathy-idle:5611): tp-glib/im-DEBUG: tp_text_mixin_acknowledge_pending_messages: acknowleding message id 12

***MEMORY-ERROR***: telepathy-idle[5611]: GSlice: assertion failed: sinfo->n_allocated > 0