Simon, On Tue, Oct 10, 2023 at 5:58 PM Simon Glass <s...@google.com> wrote: > > On Tue, 10 Oct 2023 at 02:16, Yurii Monakov <monako...@gmail.com> wrote: > > > > Unexpected 'Esc' key presses are accumulated internally, even if it is > > already clear that the current escape sequence is invalid. This results > > in weird behaviour. For example, the next character after 'Esc' key > > simply disappears from input and 'Unknown command' is printed > > after 'Enter'. > > > > This commit fixes some issues with extra 'Esc' keys entered by user: > > > > 1. Sequence <Esc><Esc><Enter> right after autoboot stop gives: > > => > > nknown command 'ry 'help' > > => > > 2. Sequence <Esc><p><r><i><Enter> gives: > > => ri > > Unknown command 'ri' - try 'help' > > => > > 3. Extra 'Esc' key presses break backspace functionality. > > > > Signed-off-by: Yurii Monakov <monako...@gmail.com> > > --- > > Changes for v2: > > - add tests and reword commit message > > Changes for v3: > > - fix indentation > > > > common/cli_getch.c | 2 ++ > > test/common/cread.c | 12 ++++++++++++ > > 2 files changed, 14 insertions(+) > > Reviewed-by: Simon Glass <s...@chromium.org> > > Unfortunately this shows a design flaw, one which is hard to fix in general. > But this does improve it. > > The flaw is that we assume that character sequences have a time gap between > them, which allows figuring out when a sequence has finished. > > But when starting up there may be buffered output with no gaps. I don't think > there is a general fix for this problem. One option is to have a special mode > at the start, where escape sequences are ignored. But the user may press an > arrow key on startup. > > So I don't have anything much to suggest here. Let's see how this fix goes. > Perhaps it is enough. > > Regards, > Simon
> One option is to have a special mode at the start, where escape sequences are > ignored I think that there is no reason to emit parts of invalid escape sequences, as current code does. There is a very little chance (at least for a human being) to input such sequences by intent. > But the user may press an arrow key on startup. As a fix, autoboot code can check for 'Esc' and keep it as a part of input string. Best Regards, Yurii
