The previous version assumed the first non-digit after the CSI was the
Final Byte, for example the first semicolon in the "\E[?1;2c" report.
It then treated all subsequent bytes as typed characters.
According to Standard ECMA-48 (Fifth Edition - June 1991), there may
be any number of Parameter Bytes in the range 0x30 to 0x3F, and then
any number of Intermediate Bytes in the range 0x20 to 0x2F, between
the CSI and the Final Byte.
This version still does not support control sequences longer than
ITRM_IN_QUEUE_SIZE bytes.
Actions can now be bound to e.g. Ctrl-Alt-A. The keybinding code also
supports other combinations of modifiers, like Shift-Ctrl-Up, but the
escape sequence decoder doesn't yet.
Don't let Ctrl-Alt-letter combinations open menus.
There is no need to check whether ev->ev == EVENT_KBD;
if decode_terminal_escape_sequence called
decode_terminal_mouse_escape_sequence, then the former neither modified
kbd.key nor passed &kbd to the latter, so kbd.key remains KBD_UNDEF.
If ev->ev was not checked, then it should not be trusted either.
So reinitialize the whole *ev if a keyboard event was indeed found.
Also list the capnames with which the escape sequences could be
read from Terminfo, and the ECMA-48 interpretations of the bytes
(parenthesized if they seem unrelated to the keys). This is in
preparation for fixing bug 96.
decode_terminal_escape_sequence() used to handle both, but
there is now a separate decode_terminal_application_key()
for ESC O. I have not yet edited decode_terminal_escape_sequence();
there may be dead code in it.
If there is e.g. ESC [ in the input buffer, combine that to Alt-[.
Check the first character too; don't blindly assume it is ESC, as
it can be NUL as well. Note this means you can no longer activate
the main menu by pressing Ctrl-@ (or Ctrl-Space on some terminals).
Otherwise, the timeout could cause ELinks to resume reading from
the terminal device while another process is still using it.
This actually happened in a test.
On entry to some functions that could resume reading from the device,
assert that the terminal has not been blocked.
