This is used by, e.g., tmux.

We do not need to disable the previous ncv definition, because
there is not previous definition.

With ncv set to 3, we prevent st from displaying A_STANDOUT and
A_UNDERLINE with colors while our virtual terminal is capable of it.

The current acsc entry, copied from xterm was not exposing capability to
display arrows.

The majority now using the Linux behaviour. Minorities have to live in their
ghettos.

ncurses wasn't able to detect the delete-character key as KEY_DC.  This
patch fixes that.

kdch1 was defined as "\0177", but terminfo(5) states:
	... characters may be given as three octal digits after a \.

The delete-character key is correctly defined in config.def.h.

Use the terminfo delay syntax ($<x>) in our flash capability to avoid
hardcoding a fixed delay in redraw() when called from tsetmode() with
DECSCNM.
We need to turn on the npc capability so that delays are made with
xon/xoff instead of padding characters.

These are needed by ncurses to correctly handle the switch between line
drawing. The changes to the alternative characterset code already fixed the
urwid hack.

St has enacs, which must be printed if a program requires to use
the alternate charset (graphic charset), that in st case was to
select charset graphic for G1, but it was not useful
at all because smacs and rmacs were always redefining the value
of G0.

DEL key has to generate the sequence ^[P in application mode,
because such sequence means delete current character. It implies
that the character sent in keypad mode must be ^? (DEL character).

This capability indicates that underscore '_' overstrike current
letter under the cursor. It means that you can generate a
underline 'b' using 'b^H_', because it writes a 'b' then backward
one characther and then overstrike '_'. St has not such behaviour,
so it is an error to have this capability.

Backspace key must generate the backspace character (\010) and
Delete key must generate the delete character (\0177). In
some systems the kernel configuration for erasing previous character
is \0177, so some programs (for example cat, ed, mail, ...), can not
understand the correct meaning of backspace. In this cases it is only
needed this command:

	stty erase 

These capabilities inform to programs how print in local printer
of the terminal.

rmul means "exit underline mode", so a full reset of all
the attributes is not the correct way of exiting from
underline mode, because it is going to modify also another
attributes not related.

Some programs don't check the value of km and use smm and rmm
capabilites, and they cause the terminal change to meta enabled
mode even in cases where is not desirable.

Allmost all people is using the terminal waiting that meta sends
escape, so rmm and smm are not needed. If someone needs meta
sets 8 bit he can use the correct terminfo definition in TERM.

- Shift + End : Delete until end of line.
    - Control + End : Delete until end of screen.

When  the End  key is  pressed  without any  modifier is  not generated  the
correct sequence for it  (going to the end of the  screen), because the size
of the  terminal is not known,  so it is  not possible write a  sequence for
this purpouse.
---
 config.def.h |   10 ++++++++--
 st.info      |    2 ++
 2 files changed, 10 insertions(+), 2 deletions(-)

Del : Delete character under cursor.
    Shift + Del : Delete the line under cursor.
    Ctrl + Del: Delete the full screen.
---
 config.def.h |   16 ++++++++++++----
 st.info      |    2 ++
 2 files changed, 14 insertions(+), 4 deletions(-)

Insert key stands for a key which allows enter or leaves insert mode, so let
it generates the correct sequence to change between these modes:

   - Insert: Enter in insert mode.
   - Shift + Insert: Leave insert mode (replace mode).
   - Control + Insert: Insert a blank line.

Like Shift + Insert also paste text, if a user want this feature be full
functional he has to modify such shortcut.
---
 config.def.h |   16 ++++++++++++----
 st.info      |    3 +++
 2 files changed, 15 insertions(+), 4 deletions(-)

ka1 stands for upper left of keypad, so the correct value is the one
generated by Home in application keypad mode.
---
 st.info |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

This patch adds the keys for the keypad (in both modes, application mode or
ansi mode) and function keys. It uses the same convention than xterm and
instead of using the XK_Fxx values it generates them using F1-F12 and
modifiers. For example:

   F1 -> ^[OP
   F1 + Shift = F13 -> ^[[1;2P
   F1 + Control = F25 -> ^[[1;5P
   F1 + Mod2 = F37 -> ^[[1;6P
   F1 + Mod1 = F49 -> ^[[1;3P
   F1 + Mod3 = F61 -> ^[[1;4P

It is also important notice than the terminfo capability kIC (shifted insert
key) only can be generated using the keypad keyboard, because the shorcut
for selection paste is using the same combination.

After this path the number of elements in the Key array becomes high, and
maybe a sequencial search is not enough efficient now.
---
 TODO         |    6 +---
 config.def.h |  102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++-
 st.info      |   70 ++++++++++++++++++++++++++++++++++++++--
 3 files changed, 169 insertions(+), 9 deletions(-)

Since there isn't any terminfo capability for control and meta modifiers for
arrows keys it is necessary use the same that almost terminal emulators use,
because there are a lot of programs which have these codes hardcoded.

This cause also that shift combinations are also changed, but in this case
this is not a problem since there are terminfo capabilities for them. After
this patch shift-up and shift-down continue not working in emacs with
TERM=st, but they work with TERM=xterm, so it is possible some other changes
are necessary in the terminfo entry.
---
 config.def.h |   16 ++++++++++++----
 st.info      |    8 ++++----
 2 files changed, 16 insertions(+), 8 deletions(-)

Usually the arrow keys generate the ANSI sequence which terminal will
understand like a movement, so it is not necessary any dealing for them, the
program can not know if the sequence is generate for a echo key or directly
from the program. If you need really know if the key was pressed then you
need activate the keypad mode where the keys will generate a special code
for each keypad key.

The terminfo capabilities kcub1, kcud1, kcuf1 and kcuu1 are used for this
keypad code, not for the sequence generate in the ansi mode.
---
 st.info |    8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Keypad mode is used for detecting when keys in the auxiliary keypad are
pressed, while cursor mode is used for detecting when a cursor is pressed,
but they are different modes.

St was mixing both modes and DECPAM and DECPNM modified the cursor mode, and
this was incorrect.
---
 st.c    |    5 +++--
 st.info |    4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

charsets.

Taken from the description:

When tput init is executed the list of task performed are (taken from
terminfo(5)):

              run the program
                     iprog

              output is1 is2

              set the margins using
                     mgc, smgl and smgr

              set tabs using
                     tbc and hts

              print the file
                     if

              and finally
                     output is3.

When reset is executed, a more stronger initialization process is performed,
so the terminal can return from an unknown state. rs1, rs2 and rs3 are used
in this case instead of
using is1, is2 and is3.

This patch makes is2 = rs2, resets insert mode and set normal keypad
mode. For rs1 it performs a full initilization using ^[c.

---
 st.info |    2 ++
 1 file changed, 2 insertions(+)

This sequence clears tab stops in the terminal. If the argument is not present
or is zero, then removes the tab stop of the current horizontal position. If
the argument is 3 then removes all the tab stops of the terminal. It was
necessary modify the terminfo entry tbc, because it has \E[2g instead of the
correct \E[3g.

Signed-off-by: Roberto E. Vargas Caballero <k0ga@shike2.com>
---
 st.c    |   12 ++++++++++++
 st.info |    2 +-
 2 files changed, 13 insertions(+), 1 deletion(-)