_get_lines_from_file() assumes loader.get_source() always exists

[guido@…]

PEP 302 says that loaders may *optionally* implement get_source(). It also says that it may return None.

django/views/debug.py line 196 assumes that it always exists and never returns None.

Here's a patch that fixes this.

[guido@…]

Patch for django/views/debug.py

[Collin Grady <cgrady@…>]

Is the loader is not None bit needed since you're adding hasattr()?

hasattr(None, "get_source") is False, so that seems to cover both cases on its own :)

[guido@…]

True, but it does become more obscure that way IMO. Anyway, your choice.

[Malcolm Tredinnick]

(In [7063]) Fixed #6359 -- Fixed an oversight in the debug output: template loaders need not have a get_source() method. Thanks, Guido van Rossum.