If the user:
#1 - disables the TUI
#2 - resizes the terminal
#3 - and then re-enables the TUI
the next wgetch() returns KEY_RESIZE. This indicates to the ncurses
client that ncurses detected that the terminal has been resized. We
don't handle KEY_RESIZE anywhere, so it gets passed on to readline
which interprets it as a multibyte character, and then the end result
is that the first key press after enabling the TUI is misinterpreted.
We shouldn't really need to handle KEY_RESIZE (and not all ncurses
implementations have that). We have our own SIGWINCH handler, and,
when we re-enable the TUI, we explicitly detect terminal resizes and
resize all windows. The reason ncurses currently does detects a
resize is that something within tui_enable forces a refresh/display of
some window before we get to do the actual resizing. Setting a break
on ncurses' 'resizeterm' function helps find the culprit(s):
(top-gdb) bt
#0 resizeterm (ToLines=28, ToCols=114) at ../../ncurses/base/resizeterm.c:462
#1 0x0000003b42812f3f in _nc_update_screensize (sp=0x2674730) at ../../ncurses/tinfo/lib_setup.c:443
#2 0x0000003b0821cbe0 in doupdate () at ../../ncurses/tty/tty_update.c:726
#3 0x0000003b08215539 in wrefresh (win=0x2a7bc00) at ../../ncurses/base/lib_refresh.c:65
#4 0x00000000005257cb in tui_refresh_win (win_info=0xd73d60 <_locator>) at /home/pedro/gdb/mygit/src/gdb/tui/tui-wingeneral.c:60
#5 0x000000000052265b in tui_show_locator_content () at /home/pedro/gdb/mygit/src/gdb/tui/tui-stack.c:269
#6 0x00000000005273a6 in tui_set_key_mode (mode=TUI_COMMAND_MODE) at /home/pedro/gdb/mygit/src/gdb/tui/tui.c:321
#7 0x00000000005278c7 in tui_enable () at /home/pedro/gdb/mygit/src/gdb/tui/tui.c:494
#8 0x0000000000527011 in tui_rl_switch_mode (notused1=1, notused2=1) at /home/pedro/gdb/mygit/src/gdb/tui/tui.c:108
That is, tui_enable calls tui_set_key_mode before we've resized all
windows, and that refreshes a window as side effect.
And if we're already debugging something (there's a frame), then we'll
instead show a window from within tui_show_frame_info:
(top-gdb) bt
#0 resizeterm (ToLines=28, ToCols=114) at ../../ncurses/base/resizeterm.c:462
#1 0x0000003b42812f3f in _nc_update_screensize (sp=0x202e6c0) at ../../ncurses/tinfo/lib_setup.c:443
#2 0x0000003b0821cbe0 in doupdate () at ../../ncurses/tty/tty_update.c:726
#3 0x0000003b08215539 in wrefresh (win=0x2042890) at ../../ncurses/base/lib_refresh.c:65
#4 0x00000000005257cb in tui_refresh_win (win_info=0xd73d60 <_locator>) at /home/pedro/gdb/mygit/src/gdb/tui/tui-wingeneral.c:60
#5 0x000000000052265b in tui_show_locator_content () at /home/pedro/gdb/mygit/src/gdb/tui/tui-stack.c:269
#6 0x0000000000522931 in tui_show_frame_info (fi=0x16b9cc0) at /home/pedro/gdb/mygit/src/gdb/tui/tui-stack.c:364
#7 0x00000000005278ba in tui_enable () at /home/pedro/gdb/mygit/src/gdb/tui/tui.c:491
#8 0x0000000000527011 in tui_rl_switch_mode (notused1=1, notused2=1) at /home/pedro/gdb/mygit/src/gdb/tui/tui.c:108
The fix is to resize windows earlier.
gdb/ChangeLog:
2015-02-17 Pedro Alves <palves@redhat.com>
* tui/tui.c (tui_enable): Resize windows before anything
might show a window.