When paging down beyond the visible chat buffer, the scroll position could
jump unexpectedly. This occurred because the visual distance from the bottom
(e.g. 6 lines until the last message) wasn’t preserved after loading new
messages from the DB.
This patch fixes that by capturing the visual offset (`current_offset`) before
the DB fetch and reapplying it after, based on the y-position of the final
buffer entry. This ensures consistent and smooth scroll transitions, even
as message heights vary.
In addition to fixing the visual glitch, this commit introduces a targeted
performance optimization: once the bottom of the chat has been reached
(`WIN_SCROLL_REACHED_BOTTOM`), we skip expensive operations entirely —
including datetime lookups and entry formatting — during further page_down
events. This reduces performance stalls
during rapid paging (e.g. holding the Page Down key at the bottom of the scrolling area).
This update also adapts to the recent change in `chatwin_db_history()`,
which now returns a `db_history_result_t` instead of `gboolean`, allowing
correct differentiation between an empty result and an actual DB error.
Together, these changes:
- Fix a scroll-jump bug in `page_down`
- Improve performance and responsiveness during rapid navigation
- Align with improved DB result handling
The function did not decref the Python object on type error paths,
resulting in a reference count leak. This caused memory to accumulate
over time. Added Py_XDECREF on all early return paths to properly free
the Python object reference and prevent leaks.
- Introduce static helper `_truncate_datetime_suffix()` to safely trim datetime strings, removing unwanted suffixes like timezone offsets
- Replace manual string management with auto_gchar and g_strdup for safer, clearer ownership and to prevent leaks
- Add safety checks and logging warnings for unexpected datetime string lengths or null pointers
- Refactor _mam_rsm_id_handler to use the helper function and updated string handling
- Change log_database_get_previous_chat parameters for consistent ownership semantics, avoiding double frees and mem leaks
- Overall improve stability and prevent memory leaks during log database queries
