Test for 5447 and for copy-mode zero line crash.

regress/copy-mode-source-blank.sh

@@ -0,0 +1,63 @@
+#!/bin/sh
+
+# Trimming a blank source must leave a visible line for cursor reflow.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export PATH TERM
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+
+fail()
+{
+	echo "$*" >&2
+	exit 1
+}
+
+cleanup()
+{
+	$TMUX kill-server 2>/dev/null
+}
+trap cleanup 0
+trap 'exit 1' 1 2 3 15
+
+$TMUX new-session -d -x80 -y24 -s test 'sleep 100' || exit 1
+$TMUX set-option -g window-size manual || exit 1
+$TMUX new-window -t test:1 'sleep 100' || exit 1
+$TMUX resize-window -t test:0 -x20 -y24 || exit 1
+
+# Exercise widening, narrowing, and equal widths with no source history.
+for pair in '0 1' '1 0' '1 2'; do
+	set -- $pair
+	if [ "$2" = 2 ]; then
+		$TMUX new-window -t test:2 'sleep 100' || exit 1
+		$TMUX resize-window -t test:2 -x80 -y24 || exit 1
+	fi
+	source=test:$1.0
+	target=test:$2.0
+	[ "$($TMUX display-message -p -t "$source" '#{history_size}')" = 0 ] ||
+		fail "source has unexpected history"
+	$TMUX copy-mode -s "$source" -t "$target" || exit 1
+	$TMUX has-session -t test || fail "server died copying blank source"
+	[ "$($TMUX display-message -p -t "$target" \
+	    '#{pane_in_mode} #{copy_cursor_x} #{copy_cursor_y}')" = '1 0 0' ] ||
+		fail "blank source did not enter copy mode at the first cell"
+	$TMUX send-keys -t "$target" -X cancel || exit 1
+done
+
+# Real content still trims trailing empty lines, clamping the cursor to beta.
+$TMUX respawn-pane -k -t test:0.0 \
+	"printf 'alpha\r\nbeta\r\n\r\n\r\n'; exec sleep 100" || exit 1
+i=0
+while [ "$($TMUX display-message -p -t test:0.0 '#{cursor_y}')" != 4 ]; do
+	i=$((i + 1))
+	[ "$i" -lt 10 ] || fail "source output did not arrive"
+	sleep 1
+done
+$TMUX copy-mode -s test:0.0 -t test:1.0 || exit 1
+[ "$($TMUX display-message -p -t test:1.0 \
+    '#{pane_in_mode} #{copy_cursor_y} #{copy_cursor_line}')" = '1 1 beta' ] ||
+	fail "nonblank source content or trailing-line trimming changed"
+
+exit 0