Add data structure to term->vt. This structure tracks the free-form
data that is passed-through, and the handler to call at the end.
Intermediates and parameters are collected by the normal VT
parser. Then, when we enter the passthrough state, we call dcs_hook().
This function checks the intermediate(s) and parameters, and selects
the appropriate unhook handler (and optionally does some execution
already).
In passthrough mode, we simply append strings to an internal
buffer. This might have to be changed in the future, if we need to
support a DCS that needs to execute as we go.
In unhook (i.e. when the DCS is terminated), we execute the unhook
handler.
As a proof-of-concept, handlers for BSU/ESU (Begin/End Synchronized
Update) has been added (but are left unimplemented).
XTerm seems to ignore these when in UTF-8 mode. Since we _only_
support UTF-8, we don't need to recognize these control characters at
all.
However, it may be good to have them here for reference. So add them,
but commented out, along with their corresponding 7-bit
versions (which we _do_ recognize and implement).
When we insert an auto-newline, we must make sure we don't try to move
outside the terminal window.
This can for example happen when a scrolling region have been
configured, and the cursor is **outside** the scrolling
region (i.e. it's in the bottom margin).
Having them as error messages was nice when we where still missing
lots of sequences.
Now we don't anymore, and these just spam stdout as well as syslog
when e.g. cat:ing binary data.
In most states, most 8-bit values are no-ops. This is already handled;
action() recognizes ACTION_NONE as a no-op. Thus, all we need to do is
remove the assertion.
* It takes a parameter, that indicates the number of tab stops to move
through
* Use the tab stops defined in the tab stops list, not hard coded mod
8 columns.
There were actually two bugs here:
* When checking for a tab stop, make sure the new tab stop is at a
different column. Otherwise you can't tab away from a tab stop.
* When there aren't any tab stops configured, or when we're already
beyond the last tab stop, then tab to the last column (at least I
think that's what we're supposed to do).
