Add --no-context-separator option

[MoSal]

--context-separator="" still adds a new line separator, and changing
that would be a breaking change.

This new option has clear intent, and preserves backward compatibility.

[BurntSushi]

What is your use case for this?

If we can make --context-separator '' work, then I'd prefer that. Even if it's technically a breaking change, that's the kind of change I'm generally okay with. We can just introduce it in the ripgrep 12 release.

[MoSal]

What is your use case for this?

Let's take filtering M3U playlist files as an example. One can easily get the URL/file corresponding to the filtered playlist item with -A1. So basically you can echo #EXTM3U which is the header, and do the filtering, and you get a valid sub-playlist as output.

If we can make --context-separator '' work, then I'd prefer that.

The issue with that solution is providing a way for users to get the old behavior back. Using \n as a separator would give two empty lines not one. If we special-case \n, then \n would print one new line and \n\n would print three!

If you still want to go that route, the patch is ready.

[BurntSushi]

I see. OK, I think I buy this, but we should not add a short flag for this.