Don't crash when trying to complete broken mappings.

Show the traceback when something goes wrong while reading input in the REPL
due to completer bugs or other bugs. Don't crash the REPL.

Author: jonathanslenders

ptpython/completer.py

@@ -505,6 +505,10 @@ def abbr_meta(text: str) -> str:
                                 display=f"[{k_repr}]",
                                 display_meta=abbr_meta(self._do_repr(result[k])),
                             )
+                        except KeyError:
+                            # `result[k]` lookup failed. Trying to complete
+                            # broken object.
+                            pass
                         except ReprFailedError:
                             pass
 
@@ -521,6 +525,10 @@ def abbr_meta(text: str) -> str:
                                     display=f"[{k_repr}]",
                                     display_meta=abbr_meta(self._do_repr(result[k])),
                                 )
+                            except KeyError:
+                                # `result[k]` lookup failed. Trying to complete
+                                # broken object.
+                                pass
                             except ReprFailedError:
                                 pass
 

ptpython/repl.py

@@ -135,6 +135,12 @@ def run(self) -> None:
                     text = self.read()
                 except EOFError:
                     return
+                except BaseException as e:
+                    # Something went wrong while reading input.
+                    # (E.g., a bug in the completer that propagates. Don't
+                    # crash the REPL.)
+                    traceback.print_exc()
+                    continue
 
                 # Run it; display the result (or errors if applicable).
                 self.run_and_show_expression(text)
@@ -192,6 +198,12 @@ async def run_async(self) -> None:
                         text = await loop.run_in_executor(None, self.read)
                     except EOFError:
                         return
+                    except BaseException:
+                        # Something went wrong while reading input.
+                        # (E.g., a bug in the completer that propagates. Don't
+                        # crash the REPL.)
+                        traceback.print_exc()
+                        continue
 
                     # Eval.
                     await self.run_and_show_expression_async(text)