From 8900d71e388043726fece2695b9b0ffc9a0d7afb Mon Sep 17 00:00:00 2001 From: Patrick Palka Date: Wed, 22 Apr 2015 19:25:55 -0400 Subject: [PATCH] Explicitly call rl_resize_terminal() in TUI's SIGWINCH handler In readline 6.3, the semantics of SIGWINCH handling has changed. When a SIGWINCH signal is raised, readline's rl_sigwinch_handler() now does not immediately call rl_resize_terminal(). Instead it sets a flag that is checked by RL_CHECK_SIGNALS() at a point where readline has control, and calls rl_resize_terminal() if said flag is set. This change is item (c) in https://cnswww.cns.cwru.edu/php/chet/readline/CHANGES c. Fixed a bug that caused readline to try and run code to modify its idea of the screen size in a signal handler context upon receiving a SIGWINCH. This change in behavior is important to us because TUI's tui_sigwinch_handler() relies on the assumption that by the time it's called, readline will have updated its knowledge of the terminal dimensions via rl_resize_terminal(). Since this assumption no longer holds true, TUI's SIGWINCH handling does not work correctly with readline 6.3. To fix this issue this patch makes TUI explicitly call rl_resize_terminal() in tui_async_resize_screen() at the point where current terminal dimensions are needed. (We could call it in tui_sigwinch_handler too, but since readline avoids doing it, we are probably safer off avoiding to call it in signal handler context as well.) After this change, SIGWINCH handling continues to work properly with both readline 6.2 and 6.3. Since we no longer need it, we could now explicitly disable readline's SIGWINCH handler by setting rl_catch_sigwinch to zero early on in the program startup but I can't seem to find a good spot to place this assignment (the first call to rl_initialize() occurs in tui_initialize_readline() so the assignment should occur before then), and the handler is harmless anyway. gdb/ChangeLog: * tui/tui-win.c (tui_async_resize_screen): Call rl_resize_terminal(). --- gdb/ChangeLog | 5 +++++ gdb/tui/tui-win.c | 1 + 2 files changed, 6 insertions(+) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index f5ea3957faa..f518c6c797d 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,8 @@ +2015-04-23 Patrick Palka + + * tui/tui-win.c (tui_async_resize_screen): Call + rl_resize_terminal(). + 2015-04-22 Jon Turney * windows-nat.c (handle_output_debug_string): Don't change diff --git a/gdb/tui/tui-win.c b/gdb/tui/tui-win.c index 77218e81c8d..3cf38fc7aaa 100644 --- a/gdb/tui/tui-win.c +++ b/gdb/tui/tui-win.c @@ -848,6 +848,7 @@ tui_async_resize_screen (gdb_client_data arg) if (!tui_active) return; + rl_resize_terminal (); tui_resize_all (); tui_refresh_all_win (); tui_update_gdb_sizes (); -- 2.30.2