Fix parsing of password-command option (#6268)

[frasertweedale]

The password-command option does not parse its value correctly.
Quotes are ignored, making many kinds of commands impossible to
express (e.g. sh -c "foo | bar"). Also, cabal user-config
treats the argument list as a list of option values, rather than a
value that is a list. As a consequence, cabal user-config update corrupts the value in the config file.

Fix these issues by parsing the command as a space separated list of
tokens, and changing the getter to unwords the value and return a
singleton list. Also update the argument placeholder from
PASSWORD to COMMAND.

Fixes: #6268

Manual QA Notes

• Please, see the original bugreport that contains a short and sweet reproducer.

---

Please include the following checklist in your PR:

• Patches conform to the coding conventions.
• Any changes that could be relevant to users have been recorded in the changelog.
• The documentation has been updated, if necessary.
• Include manual QA notes if your PR relates to cabal-install.

Bonus points for added automated tests!

[ulysses4ever]

Good job here, thank you! Would it be possible to add a test?

[frasertweedale]

@ulysses4ever I added (well, extended) a test, and updated the users guide.

[frasertweedale]

bump please review when able :)

[frasertweedale]

@Kleidukos also affects cabal upload command. Suggest adding label cabal-install: cmd/upload.

[ulysses4ever]

@frasertweedale please, add a changelog as described here.

[ulysses4ever]

Predicated on the changelog, this looks good to me, thanks!

[ulysses4ever]

Also, I think it'd be nice to have manual QA for this change. I'll add a note in the OP.

[frasertweedale]

@ulysses4ever I added a changelog.d entry.

[ulysses4ever]

Thank you! Waiting for a second review…

[geekosaur]

Looks reasonable to me

[frasertweedale]

Something went wrong with mergify. Can someone advise on next steps? I logged into mergify (never used it previously) but it couldn't access the haskell dashboard or something...

[Kleidukos]

@frasertweedale no problems, thanks

[jgotoh]

Here are the results of QA:

1. Verify with latest cabal 3.10.1.0:

~/.cabal/config contains:
password-command: sh -c "ls | tail -n 1"

Running cabal user-config update results in following change in ~/.cabal/config:
password-command: sh,-c,"ls,|,tail,-n,1

=> password-command was changed, bug exists

2. Verify fix with latest cabal head:

Running cabal user-config update results in following change in ~/.cabal/config:
password-command: sh -c "ls | tail -n 1"

Same as before, so QA is passed 🥇

Edit:

hold on, I checked the wrong file, sorry. The following change occurs in my config file after running cabal-head user-config update
password-command: "sh" "-c" "ls | tail -n 1"

Is this the correct behavior? @frasertweedale

[ulysses4ever]

@jgotoh thanks a bunch!

[frasertweedale]

hold on, I checked the wrong file, sorry. The following change occurs in my config file after running cabal-head user-config update password-command: "sh" "-c" "ls | tail -n 1"

Is this the correct behavior? @frasertweedale

This is expected. The values are semantically equivalent. It's an artifact of the token parsing compared to the pretty-printing of the option values. There are two ways of representing a simple token: with quotes, or without. So unless we represent which variant was used in the option values, there is no way to ensure the string representation round-trips.

[jgotoh]

Awesome, thank you very much for your quick answer and your detailed description. Then QA is passed here! :)

[ulysses4ever]

Bugfix -- qualifies for a backport, I think.

[ulysses4ever]

@mergify backport 3.10

[mergify]

backport 3.10

✅ Backports have been created

• #9125 Fix parsing of password-command option (#6268) (backport #9002) has been created for branch 3.10 but encountered conflicts