utils and libraries: Allow values quoting in config files

[hebasto]

The using double quotes to quote command line option values with spaces
(e.g. paths) is allowed on all platforms. Options in config files are
handled in the same way now.
The config file values can be surrounded by quotation marks. This allows
for explicit using of whitespaces (e.g. in paths).

[ken2812221]

Doesn't the path with spaces in it work without quotes?
How to specify a path that has quotes at the end?

[hebasto]

@ken2812221

Doesn't the path with spaces in it work without quotes?

Yes, it works.
But it is inconsistent. Compare:
bitcoin-qt -blocksdir="/some/path/with space"
with a line in a config file
blocksdir=/some/path/with space

[hebasto]

@ken2812221

How to specify a path that has quotes at the end?

I didn't catch it. Can you provide a use case?

[practicalswift]

Concept ACK

Seems like a nice usability improvement

[maflcko]

This is a breaking change with previous versions? In any case, this needs extensive release notes documentation or update the documentation of our config file parser. (Not sure if we have that user documentation already)

[ken2812221]

If someone is using a weird path datadir=/path/contains/quote", It would strip out the ". It would also strip it out if it only appear once. Also, in command line you can specify -datadir=/path/"contain whitespace", it is still inconsistent with conf file.

[hebasto]

@MarcoFalke
Thank you for your review.

This is a breaking change with previous versions? In any case, this needs extensive release notes documentation or update the documentation of our config file parser. (Not sure if we have that user documentation already)

#14427 addressed to your concerns about user documentation. Would you mind to review it?

[hebasto]

@ken2812221
Thank you for your review.

Also, in command line you can specify -datadir=/path/"contain whitespace", it is still inconsistent with conf file.

My bad. I'm going to fix it.

[hebasto]

@ken2812221
Fixed. Please re-review.

[ryanofsky]

I think it's better for config file parser to either:

1. not interpret quotes at all
2. interpret quotes in a very simple way like https://en.wikipedia.org/wiki/INI_file#Quoted_values
3. interpret quotes in a documented way like https://github.com/toml-lang/toml#user-content-string

than to do what this PR does and try to make config file quoting vaguely resemble posix shell quoting and windows msvcrt command line quoting without actually implementing either scheme.

[hebasto]

@ryanofsky
Thank you for your review.

interpret quotes in a very simple way like https://en.wikipedia.org/wiki/INI_file#Quoted_values

Agree. Done. Please re-review.

[ken2812221]

Concept ACK. This is much better. Also the use can specify any characters that it wants.

[maflcko]

This needs tests before merge.

[hebasto]

@MarcoFalke

This needs tests before merge.

I've modified the src/test/util_tests.cpp unit tests. Should this patch be placed in this PR?

[laanwj]

i'm not sure this is worth it

• you've always been able to use spaces in .conf arguments, this just needs to be documented better
• as far as I know, explicit quoting is not part of .ini file format as used in other software, and that's what our conf format is based on (but let me know otherwise if this is wrong!)
• as @MarcoFalke mentioned by this is a breaking change, what if you want to have " around a value? you'll now end up with two sets?

[meshcollider]

as @MarcoFalke mentioned by this is a breaking change, what if you want to have " around a value? you'll now end up with two sets?

Especially in, for example, an rpcpassword or something

[laanwj]

yes, there is plenty of tooling/scripting that assumes you can just dump a value after =, this will all have to be rewritten to take this into account

(edit: although arguably, #13143 already complicates this, and provides a use-case for quoting maybe?!)

[laanwj]

Closing in favor of #14497