Clean up image support and add regression tests

regress/image-resize-many-placements.sh

@@ -0,0 +1,38 @@
+#!/bin/sh
+
+# Widening a pane restores clipped columns for every image placement.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C
+export TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -Limage-resize-outer$$ -f/dev/null"
+TMUX2="env -u TMUX LC_ALL=C $TEST_TMUX -Limage-resize-inner$$ -f/dev/null"
+TMP=$(mktemp)
+trap "$TMUX kill-server 2>/dev/null; $TMUX2 kill-server 2>/dev/null; rm -f $TMP" 0 1 15
+
+# White placements stay behind the final red placement.
+$TMUX2 new-session -d -x 8 -y 4 "
+	i=0
+	while [ \$i -lt 64 ]; do
+		printf '\\033_Ga=T,q=2,C=1,f=32,s=1,v=1,c=16,r=1;/////w==\\033\\\\'
+		i=\$((i + 1))
+	done
+	printf '\\033_Ga=T,q=2,C=1,f=32,s=1,v=1,c=16,r=1;/wAA/w==\\033\\\\'
+	sleep 30" || exit 1
+[ "$($TMUX2 display-message -p '#{image_support}')" = 0 ] && exit 0
+$TMUX2 set -g status off || exit 1
+$TMUX new-session -d -x 8 -y 4 "$TMUX2 attach-session" || exit 1
+$TMUX set -g status off || exit 1
+sleep 1
+
+$TMUX capture-pane -pS0 -E0 >$TMP || exit 1
+[ "$(cat $TMP)" = '........' ] || exit 1
+$TMUX resize-window -x 16 -y 4 || exit 1
+sleep 1
+$TMUX capture-pane -pS0 -E0 >$TMP || exit 1
+[ "$(cat $TMP)" = '................' ] || exit 1
+
+exit 0