better faulty encoding detection

tests/test_gui_core.py

@@ -21,6 +21,7 @@ from pypdf import PdfReader, PdfWriter
 from copienator import (
     CliError,
     EvaluationWorkspace,
+    ExitCode,
     WorkspaceNotFoundError,
     WorkspaceValidationError,
     atomic_update_json,
@@ -1058,6 +1059,26 @@ class StandardCliTests(unittest.TestCase):
             previous_image, previous_json, previous_meta
         )
 
+    def test_plotting_accepts_lowercase_and_uppercase_previous_shortcuts(self) -> None:
+        module = self.modules["plotting"]
+        root = Mock()
+        root.winfo_screenwidth.return_value = 1200
+        root.winfo_screenheight.return_value = 800
+        label = Mock()
+
+        with patch.object(module.tk, "Label", return_value=label), patch.object(
+            module.ImageViewer, "poll_queue"
+        ):
+            viewer = module.ImageViewer(
+                root,
+                SimpleNamespace(root=Path("/evaluation")),
+                set(),
+                queue.Queue(),
+            )
+
+        root.bind.assert_any_call("p", viewer.on_previous)
+        root.bind.assert_any_call("P", viewer.on_previous)
+
     def test_plotting_validates_plain_and_directional_labels(self) -> None:
         module = self.modules["plotting"]
         self.assertEqual(
@@ -1317,6 +1338,16 @@ class StandardCliTests(unittest.TestCase):
             self.assertEqual(result["list"][0]["label"], "??Ex 10 : 1)a)")
             self.assertIn("keeping them with a ?? prefix", output.getvalue())
 
+    def test_correction_response_preserves_ambiguous_latex_commands(self) -> None:
+        module = self.modules["correction"]
+        parsed = module.parse_correction_response(
+            r'[{"result":{"feedback":[{"text":"$\forall x, f \big(x\big) \to x$"}]}}]'
+        )
+        self.assertEqual(
+            parsed[0]["result"]["feedback"][0]["text"],
+            r"$\forall x, f \big(x\big) \to x$",
+        )
+
     def test_correction_overwrite_keeps_previous_state_until_a_commit(self) -> None:
         module = self.modules["correction"]
         with tempfile.TemporaryDirectory() as directory:
@@ -1774,6 +1805,23 @@ class StandardCliTests(unittest.TestCase):
             r"Formulas $\frac{1}{2}$, $\theta \equiv 0 [2\pi]$, "
             r"$e \times x$, and [\negthinspace[0,n]",
         )
+        decoded_math_commands = (
+            "$"
+            + "\x0corall x, f "
+            + "\x08ig(x\x08ig) "
+            + "\to "
+            + "\text{false}$"
+        )
+        self.assertEqual(
+            module.clean_string(decoded_math_commands, {}),
+            r"$\forall x, f \big(x\big) \to \text{false}$",
+        )
+        self.assertEqual(
+            module.unresolved_math_control_paths(
+                {"feedback": ["Plain\fprose", "$unknown\fform$"]}
+            ),
+            ["$['feedback'][1]"],
+        )
         self.assertEqual(
             module.clean_string("x ∈ A and B ⊂ C", {}),
             r"x \ensuremath{\in} A and B \ensuremath{\subset} C",
@@ -1800,6 +1848,19 @@ class StandardCliTests(unittest.TestCase):
             self.assertEqual((evaluation / "correction.json").read_bytes(), cleaned)
             self.assertEqual(backup.read_bytes(), original)
 
+        with tempfile.TemporaryDirectory() as directory:
+            evaluation = Path(directory) / "Exam"
+            evaluation.mkdir()
+            atomic_write_json(
+                evaluation / "correction.json",
+                {"text": "$unknown\fcommand$"},
+            )
+            output = io.StringIO()
+            with redirect_stdout(output):
+                result = module.run(EvaluationWorkspace(evaluation))
+            self.assertEqual(result, ExitCode.PARTIAL)
+            self.assertIn("$['text']", output.getvalue())
+
     def test_manual_resolution_with_no_actions_is_safe(self) -> None:
         module = self.modules["resolve_manual"]
         with tempfile.TemporaryDirectory() as directory: