Replace DOS line endings with LF

[xknown]

DOS line endings are not currently stripped from the wp-config files, which results in extra lines being added to the modified file.

Fixes wp-cli/config-command#160
Related: wp-cli/wp-cli#5859

[schlessera]

@xknown This is not something that can be solved with a simple str_replace(), I'm afraid.

What the code does with your changes seems worse than before.

Imagine the scenario where you have two regular blank lines in the standard notation for servers:

\n\r\n\r

The logic with this PR will first replace the middle part of that sequence, breaking the two individual blank lines. Then, as it completes, the final result will be this:

\n\n\n\n

So, for the more common configurations, it will end up turning two blank lines into four blank lines.

To solve this properly, we would need to switch away from str_replace() and use a regular expression that considers entire groups in one go and detects the patterns.

[xknown]

@xknown This is not something that can be solved with a simple str_replace(), I'm afraid.

What the code does with your changes seems worse than before.

Imagine the scenario where you have two regular blank lines in the standard notation for servers:

\n\r\n\r

The logic with this PR will first replace the middle part of that sequence, breaking the two individual blank lines. Then, as it completes, the final result will be this:

\n\n\n\n

That's not really the case though, because the str_replace will first replace\n\r (or \r\n) by a single \n. However, I agree that using a regular expression might probably be better to only replace those characters where it makes most sense.

[schlessera]

@xknown Indeed, you're right, my bad. I tested this in 3v4l.org and it seems to reliably work with all constellations.

[schlessera]

Can we add double blank lines in multiple constellations here as well just to fully demonstrate it works without splitting the combinations?

[xknown]

Added them in dd6f0f9, however I think there's another bug that happens when the provided config file has a multiline string containing any of the replaced characters. In theory, we shouldn't be touching them. To fix it properly, we might require a proper PHP parser though, not sure if it already exists somewhere in wp-cli?

[schlessera]

No, we don't have a PHP Parser around, we tried to avoid adding dependencies to this to make sure it doesn't randomly break from conflicts.

[schlessera]

however I think there's another bug that happens when the provided config file has a multiline string containing any of the replaced characters.

Can you open a separate issue for this?