Add a limit on image count and size.

regress/image-sixel-limits.sh

@@ -0,0 +1,76 @@
+#!/bin/sh
+
+# Check image quotas, last use order, copied grids and released image slots.
+
+PATH=/bin:/usr/bin
+TERM=screen
+export TERM
+[ -z "$TEST_TMUX" ] && TEST_TMUX=$(readlink -f ../tmux)
+command -v python3 >/dev/null || exit 101
+
+python3 -B - "$TEST_TMUX" <<'PY'
+import sys
+from image_test import image_test, sixel
+from image_terminal import Terminal
+
+
+def image(colour):
+    """Build one solid image cell which advances the cursor by one row."""
+    return sixel(8, 16, [colour], [0] * (8 * 16))
+
+
+def snapshot(test, client, rows):
+    """Check the image cells in the first column after a full redraw."""
+    test.redraw()
+    terminal = Terminal()
+    terminal.feed(client.data)
+    expected = {(x, y * 16 + py): colour for y, colour in rows.items()
+        for py in range(16) for x in range(8)}
+    terminal.check(expected)
+
+
+red, green, blue = (255, 0, 0), (0, 255, 0), (0, 0, 255)
+red_image = image((100, 0, 0))
+green_image = image((0, 100, 0))
+blue_image = image((0, 0, 100))
+
+with image_test(sys.argv[1]) as test:
+    client = test.attach()
+    test.emit(red_image + green_image * 999)
+    test.emit(blue_image)
+    snapshot(test, client, dict.fromkeys(range(14), green) | {14: blue})
+    # Images in scrollback count towards the quota; the oldest one is gone.
+    test.run('copy-mode')
+    test.run('send-keys', '-X', 'history-top')
+    snapshot(test, client, dict.fromkeys(range(1, 16), green))
+
+with image_test(sys.argv[1]) as test:
+    client = test.attach()
+    test.emit(red_image + green_image * 999)
+    test.run('copy-mode')
+    test.run('send-keys', '-X', 'history-top')
+    snapshot(test, client, {0: red} | dict.fromkeys(range(1, 16), green))
+    # The copied grid keeps these old images in use while a new window fills.
+    test.run('new-window', '-n', 'quota', '/bin/sh', '-c',
+        "stty raw -echo; printf '\033]2;QUOTA\007'; exec cat")
+    test.wait(lambda: test.run('display-message', '-p',
+        '#{pane_title}') == 'QUOTA')
+    test.emit(blue_image)
+    test.run('select-window', '-t', 'image:0')
+    snapshot(test, client, {0: red} | dict.fromkeys(range(1, 16), green))
+    # The first image below the redrawn rows was evicted from both grids.
+    test.run('send-keys', '-X', 'scroll-down')
+    snapshot(test, client, dict.fromkeys(range(15), green))
+    test.run('send-keys', '-X', 'cancel')
+    test.run('copy-mode')
+    test.run('send-keys', '-X', 'history-top')
+    test.run('send-keys', '-X', 'scroll-down')
+    snapshot(test, client, dict.fromkeys(range(15), green))
+
+with image_test(sys.argv[1]) as test:
+    client = test.attach()
+    # Replacing an image releases its slot rather than exhausting the quota.
+    test.emit((b'\033[H' + green_image) * 1001)
+    test.emit(b'\033[3;1H' + blue_image)
+    snapshot(test, client, {0: green, 2: blue})
+PY