When starting TUI in a terminal with 3 lines:
...
$ echo $LINES
3
$ gdb -q -tui
...
and resizing the terminal to 2 lines we run into a segfault.
The problem is that for the source window:
- the minimum height is 3 (the default), but
- the maximum height is only 2 because there are only 2 lines.
This discrepancy eventually leads to a call to newwin in make_window with:
...
(gdb) p height
$1 = 3
(gdb) p width
$2 = 56
(gdb) p y
$3 = -1
(gdb) p x
$4 = 0
...
which results in a nullptr.
This violates the assumption here in tui_apply_current_layout:
....
/* Get the new list of currently visible windows. */
std::vector<tui_win_info *> new_tui_windows;
applied_layout->get_windows (&new_tui_windows);
...
that get_windows only returns visible windows, which leads to tui_windows
holding a dangling pointer, which results in the segfault.
Fix this by:
- making sure get_windows only returns visible windows, and
- detecting the situation and dropping windows from the layout if
there's no room for them.
Tested on x86_64-linux.
Approved-By: Tom Tromey <tom@tromey.com>
PR tui/31044
Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=31044
03893ce67b