doc: add note on precedence of options in bitcoin.conf #16448

This means that given the following configuration, `regtest.rpcport` is set to `3000`:

s/is/are/

with respect to "generally", do exceptions exist?

re: #16448 (review)

with respect to "generally", do exceptions exist?

The main exception is settings like -wallet where multiple values are used. But in general the way settings are merged is insane and has lots of corner cases that should be cleaned up. #15934 has more information (look for for "strange merging behaviors" in the description).

I do think the new text in this PR is basically at the right level of detail to be understandable and set users on the right path. Getting into a lot of exceptions and special cases here would probably not be helpful.

Thanks! Will review #15934.

Thanks, I'll leave this as is for now.

Perhaps an example of network-specific vs non network-specific would be helpful. For example, IIUC the first instance of rpcport in the example below is not network-specific and the two instances after are network-specific, and so the first instance of the second two prevails. The example could take the form of inline code comments in the example below.

re: #16448 (review)

Perhaps an example of network-specific vs non network-specific would be helpful.

Best to review the document as a whole and suggest specific changes in the appropriate sections:

https://github.com/fanquake/bitcoin/blob/options_bitocin_conf/doc/bitcoin-conf.md

I agree inline code comments below could be a good idea if you want to suggest them inside the example. But the paragraph immediately before this diff explains what network specific options are, so if that section is not clear we should fix it instead of trying to explain network options a second time at the same time as describing precedence.

Thank you @ryanofsky, agreed, I overlooked the preceding paragraph.

Should you decide that comments in the example configuration are a good idea, here is one (entirely optional) version for your consideration:

regtest=1
rpcport=2000          # Non-network specific `rpcport` option
regtest.rpcport=3000  # 1st network specific `rpcport` option -> value chosen by the parser

[regtest]
rpcport=4000          # 2nd network specific `rpcport` option

I feel like adding comments would make this pretty noisy, however will leave this up to if anyone else thinks they should be added.

I know this PR has been merged now but I would have liked more comments here as @jonatack suggested. I didn't understand what was going on. I understand there is a trade-off between informing less experienced users and minimizing noise for more experienced users. Perhaps when the minimizing noise option is chosen a Bitcoin StackExchange page can be set up to include those comments. Resources like Jameson Lopp's Bitcoin Core config generator tool are useful too. Though whether you'd want to provide a link to these resources from within a config file or in a comment within the codebase I don't know...

I guess it's better to make a new PR at this point; replying on a deeply nested comment on a merged PR isn't going to make much of a difference

Though whether you'd want to provide a link to these resources from within a config file or in a comment within the codebase I don't know...

Would personally prefer to keep it more or less self-contained, external links might change and tend to go stale.

Ok, understood. Thanks