[PATCH weston] terminal: Fix crash due to race condition in init

[Yong Bakos]

On Aug 29, 2016, at 4:28 PM, Bryce Harrington <bryce at osg.samsung.com> wrote:
> 
> weston-terminal intermittently crashes on startup.  This occurs because
> some parameters in the weston_terminal structure such as data_pitch,
> don't get set to non-zero until the resize_handler() callback gets
> triggered.  That callback makes a call to terminal_resize_cells(), to
> calculate the proper values for these parameters.
> 
> On occasion, the resize handler call is slow to resolve, and the program
> proceeds to start processing characters for the terminal window.  With
> the parameters defaulting to zero, certain calculations come out wrong,
> leading the program to attempt to scroll the buffer when it shouldn't,
> and thus follows the crash.
> 
> Instead, force the call to terminal_resize_cells() during the init, with
> some dummy defaults, to ensure the parameters are always non-zero.
> 
> Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=97539
> Signed-off-by: Bryce Harrington <bryce at osg.samsung.com>

I couldn't replicate the issue, but the fix seems innocuous enough.
Someone with more experience should chime in, but this is:

Reviewed-by: Yong Bakos <ybakos at humanoriented.com>

yong


> ---
> clients/terminal.c | 1 +
> 1 file changed, 1 insertion(+)
> 
> diff --git a/clients/terminal.c b/clients/terminal.c
> index 6257cb7..34bc2c9 100644
> --- a/clients/terminal.c
> +++ b/clients/terminal.c
> @@ -2976,6 +2976,7 @@ terminal_create(struct display *display)
> 	cairo_surface_destroy(surface);
> 
> 	terminal_resize(terminal, 20, 5); /* Set minimum size first */
> +	terminal_resize_cells(terminal, 20, 5);
> 	terminal_resize(terminal, 80, 25);
> 
> 	wl_list_insert(terminal_list.prev, &terminal->link);
> -- 
> 1.9.1
> 
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