Fix invalid check

[GuillaumeGomez]

block_start is already checked just above.

Also a question about this code: shouldn't the character in common be between *_start and *_end instead of the current code?

[Kijewski]

I'm not even sure if the two characters requirement couldn't be relaxed. I guess it speeds up the parsing, but I don't think that parsing the templates will take up much of the compiling time of a non-trivial project.

[GuillaumeGomez]

Considering it's config setup, I'm not even sure if it'd have any impact at all...

[Kijewski]

Hehe, I meant the code of the parser. But no, e.g. https://github.com/djc/askama/blob/7238fe2971917f547498e761ff252244cd5c992d/askama_shared/src/parser.rs#L213-L217 does not care how long the delimiters are. Nevertheless, this could be be changed in another PR.

[GuillaumeGomez]

Oh indeed. Please open an issue! :D