Calculate real terminal size when resize detected.

Basta should not trust that a changed value of LINES reflects
the terminal size. In cases when LINES is set to a bad value,
it leaves the display in a bad state: wrong scrolling region,
wrong status line position.

As a test, try a command like "LINES=3; stty rows $LINES".
Before this change, Basta will react and move the status line
to the third line, setting up a two-line scrolling region.
With this change, Basta isn't fooled; it asks the terminal.

- New function basta.calc_current_size interrogates the
  terminal to get the size, just like
  basta.calc_prev_preserved does. The function sets up
  LINES and stty rows to the discovered terminal size.

- basta.prepare_term calls this function the second and
  subsequent time it is called.

1 files changed, 11 insertions, 0 deletions

diff --git a/basta.sh b/basta.sh
index 8b7ad38..07b268f 100644
--- a/basta.sh
+++ b/basta.sh
@@ -18,11 +18,22 @@ basta.calc_prev_reserved()
   basta_prev_reserved_rows=$((realrows - LINES))
 }
 
+basta.calc_current_size()
+{
+  local esc=$(printf "\033")
+  printf "${esc}7$esc[999;999H"
+  LINES=$(basta.get_cur_line)
+  printf "${esc}8"
+  stty rows $LINES
+}
+
 basta.prepare_term()
 {
   if [ -z "$basta_prev_reserved_rows" ] ; then
     basta.calc_prev_reserved
     printf "\n\033[A"
+  else
+    basta.calc_current_size
   fi
 
   basta_scroll_lines=$((LINES - 1))