Do not raise an error for invalid octal escape sequences (#64)

Author: barisione

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 ## 0.10.0.3
 * Fixed a bug where notifications without a payload were not recognized as such
+* Invalid octal sequences produced by GDB are left unchanged instead of causing a `UnicodeDecodeError` (#64)
 
 ## 0.10.0.2
 * Strings containing escapes are now unescaped, both for messages in error records, which were previously mangled (#57), and textual records, which were previously left escaped (#58)

pygdbmi/gdbescapes.py

@@ -166,7 +166,13 @@ def _unescape_internal(
                     raise ValueError(
                         f"Invalid octal number {octal_number!r} in {escaped_str!r}"
                     ) from exc
-            replaced = octal_sequence_bytes.decode("utf-8")
+            try:
+                replaced = octal_sequence_bytes.decode("utf-8")
+            except UnicodeDecodeError:
+                # GDB should never generate invalid sequences but, according to #64,
+                # it can do that on Windows. In this case we just keep the sequence
+                # unchanged.
+                replaced = f"\\{escaped_octal}"
 
         elif escaped_char is not None:
             # We found a single escaped character.

tests/test_pygdbmi.py

@@ -502,6 +502,9 @@ def test_unescape(self) -> None:
             with self.assertRaisesRegex(ValueError, "Invalid escape character"):
                 unescape(bad)
 
+        # An octal sequence that is not valid UTF-8 doesn't get changes, see #64.
+        assert_match(unescape(r"254 '\376'"), r"254 '\376'")
+
     def test_advance_past_string_with_gdb_escapes(self) -> None:
         """Test the advance_past_string_with_gdb_escapes function"""