Regress for damage rectangles.

regress/floating-pane-drag-ghost.sh

@@ -0,0 +1,108 @@
+#!/bin/sh
+
+# Regression test for a floating-pane drag bug: cmd_resize_pane_redraw_floating()
+# (cmd-resize-pane.c) reported damage for just a dragged floating pane's
+# content rectangle, not the one-cell border frame drawn around it (see the
+# "floating" case in screen-redraw.c, which draws that frame at
+# xoff-1/yoff-1 through xoff+sx/yoff+sy - one cell outside the pane's own
+# content area). Damage scoped to only the content area left the frame's
+# previous position undrawn as the pane moved, so dragging it left a trail
+# of un-erased border frames behind - visible as several "corners" stacked
+# up rather than just the pane's current one.
+#
+# This bug has nothing to do with images - it reproduces with a plain
+# floating pane and no image support required.
+
+PATH=/bin:/usr/bin
+TERM=screen
+LC_ALL=C.UTF-8
+export TERM LC_ALL
+
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+TMUX="$TEST_TMUX -LtestA$$ -f/dev/null"
+TMUX2="$TEST_TMUX -LtestB$$ -f/dev/null"
+
+cleanup()
+{
+	$TMUX kill-server >/dev/null 2>&1
+	$TMUX2 kill-server >/dev/null 2>&1
+}
+fail()
+{
+	echo "$*" >&2
+	cleanup
+	exit 1
+}
+
+# drag STARTCOL STARTROW ENDCOL ENDROW
+#
+# Write a plain (unmodified) SGR button-1 press, drag update and release at
+# 1-based positions to the outer pane holding the inner client - this
+# matches the default MouseDown1Border/MouseDrag1Border bindings used to
+# move or resize a floating pane by its border.
+drag()
+{
+	scol="$1"
+	srow="$2"
+	ecol="$3"
+	erow="$4"
+
+	seq=$(printf '\033[<0;%s;%sM' "$scol" "$srow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<32;%s;%sM' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 0.2
+	seq=$(printf '\033[<0;%s;%sm' "$ecol" "$erow")
+	$TMUX2 send-keys -t "$OUTER" -l "$seq" 2>/dev/null
+	sleep 1
+}
+
+cleanup
+
+TMP=$(mktemp)
+trap "cleanup; rm -f $TMP" 0 1 15
+
+$TMUX new-session -d -s inner -x 60 -y 20 'sh -c "sleep 100"' || exit 1
+$TMUX set -g mouse on
+$TMUX set -g default-command 'sh -c "sleep 100"'
+
+FLOAT=$($TMUX new-pane -d -PF '#{pane_id}' -x 16 -y 5 -X 5 -Y 5) ||
+	fail "new-pane -X -Y failed"
+FTOP=$($TMUX display-message -p -t "$FLOAT" '#{pane_top}')
+FLEFT=$($TMUX display-message -p -t "$FLOAT" '#{pane_left}')
+FWIDTH=$($TMUX display-message -p -t "$FLOAT" '#{pane_width}')
+
+$TMUX2 new-session -d -x 60 -y 20 "$TMUX attach -t inner" || exit 1
+sleep 1
+OUTER=$($TMUX2 list-panes -F '#{pane_id}' | head -1)
+[ -n "$OUTER" ] || fail "No outer pane."
+
+# Sanity check: exactly one floating pane, so exactly one top-left corner,
+# before dragging anything.
+$TMUX2 capturep -p -t "$OUTER" >$TMP || fail "capture failed"
+n=$(grep -o '┌' $TMP | wc -l)
+[ "$n" -eq 1 ] || fail "sanity: expected 1 corner before drag, found $n"
+
+# Drag the floating pane by its top border (row FTOP-1, some column within
+# its width) down several rows in a few separate steps, then release. A
+# single drag() call already does press/motion/release, so call it several
+# times in a row to simulate a multi-step real drag.
+GRABCOL=$((FLEFT + FWIDTH / 2))
+STARTROW=$FTOP
+i=0
+while [ $i -lt 6 ]; do
+	newrow=$((STARTROW + i + 1))
+	drag $((GRABCOL + 1)) $((STARTROW + i)) $((GRABCOL + 1)) $newrow
+	i=$((i + 1))
+done
+
+$TMUX2 capturep -p -t "$OUTER" >$TMP || fail "capture failed"
+
+# Exactly one top-left corner should remain - the pane's current position.
+# This is expected to fail before the fix: multiple corners (a trail of
+# un-erased frames) would remain from the intermediate drag positions.
+n=$(grep -o '┌' $TMP | wc -l)
+[ "$n" -eq 1 ] || fail "expected exactly 1 corner after drag, found $n (ghost frames left behind)"
+
+exit 0