CVS commit: src/external/bsd/nvi/dist/cl

["Michael van Elst" <mlelstv%netbsd.org@localhost>]

Module Name:    src
Committed By:   mlelstv
Date:           Fri Sep  1 07:21:01 UTC 2017

Modified Files:
        src/external/bsd/nvi/dist/cl: cl_main.c cl_screen.c

Log Message:
When resizing nvi in xterm, a scroll region is set with the old size
which garbles the display.

The scroll region is set for a terminfo scroll operation and then
reset to the current window size. While xterm lets you clear a
scroll region, there is no way to do this in terminfo except by
resetting the terminal which has a visual side effect.

Xterm actually clears the scroll region as part of the resize but
that happens before a program gets the SIGWINCH signal. When nvi sees
the SIGWINCH signal, it exits the vi mode using a scroll operation to
tidy up the display before it reenters vi mode with the new window size.

This patch does two things:
- make nvi also invoke a previous SIGWINCH handler (not sufficient,
  but that's how curses wants it).
- skip the tidy up in case of a restart (avoids the scroll region)


To generate a diff of this commit:
cvs rdiff -u -r1.5 -r1.6 src/external/bsd/nvi/dist/cl/cl_main.c \
    src/external/bsd/nvi/dist/cl/cl_screen.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.