test: extend clipboard tests to various different sizes

Check if copying 64k also works. And then try copying 200kb, both
with default settings (should be refused) and with limit raised. This
test assume already modified behavior on over the limit copy (truncate
to 0 instead of truncating to the limit).

QubesOS/qubes-issues#9296

qubes/tests/integ/basic.py

@@ -472,7 +472,9 @@ def setUp(self):
         super(TC_30_Gui_daemon, self).setUp()
         self.init_default_template()
 
-    async def _test_clipboard(self, test_string):
+    async def _test_clipboard(self, test_string,
+                              set_features=None,
+                              expect_truncated_to=None):
         testvm1 = self.app.add_new_vm(
             qubes.vm.appvm.AppVM,
             name=self.make_vm_name('vm1'), label='red')
@@ -483,6 +485,9 @@ async def _test_clipboard(self, test_string):
         await testvm2.create_on_disk()
         self.app.save()
 
+        for feature, value in (set_features or {}).items():
+            testvm1.features[feature] = value
+
         await asyncio.gather(
             testvm1.start(),
             testvm2.start())
@@ -514,6 +519,9 @@ async def _test_clipboard(self, test_string):
 
         clipboard_content = \
             open('/var/run/qubes/qubes-clipboard.bin', 'r').read().strip()
+
+        if expect_truncated_to is not None:
+            test_string = test_string[:expect_truncated_to]
         self.assertEqual(clipboard_content, test_string,
                           "Clipboard copy operation failed - content")
         clipboard_source = \
@@ -553,6 +561,29 @@ def test_000_clipboard(self):
         test_string = "test123"
         self.loop.run_until_complete(self._test_clipboard(test_string))
 
+    @unittest.skipUnless(
+        spawn.find_executable('xdotool'),
+                         "xdotool not installed")
+    def test_001_clipboard_64k(self):
+        test_string = "test123abc" * 6400
+        self.loop.run_until_complete(self._test_clipboard(test_string))
+
+    @unittest.skipUnless(
+        spawn.find_executable('xdotool'),
+                         "xdotool not installed")
+    def test_002_clipboard_200k_truncated(self):
+        test_string = "test123abc" * 20000
+        self.loop.run_until_complete(self._test_clipboard(test_string,
+            expect_truncated_to=0))
+
+    @unittest.skipUnless(
+        spawn.find_executable('xdotool'),
+                         "xdotool not installed")
+    def test_002_clipboard_200k(self):
+        test_string = "test123abc" * 20000
+        self.loop.run_until_complete(self._test_clipboard(test_string,
+            set_features={"gui-max-clipboard-size": 200_000}))
+
 
 class TC_05_StandaloneVMMixin(object):
     def setUp(self):