GCM core fails when `NO_PROXY` contains a glob pattern

[sworisbreathing]

This issue doesn't specifically fall into any of the template patterns - the authentication itself succeeds, but the behavior is incorrect because GCM core isn't actually resolving it.

When NO_PROXY/no_proxy contains a glob pattern (i.e. *.my.domain), GCM core fails with an error such as:

info: detecting host provider for 'https://git.my.domain/'...
fatal: parsing "*.my.domain" - Quantifier {x,y} following nothing.

and git falls back to using git-askpass.

I'm not getting a lot of useful info from GIT_TRACE in GCM core, but I have been able to track it down to GCM core as follows:

This fails:

$ echo -e "protocol=https\nhost=git.my.domain" | GIT_TRACE=1 ~/AppData/Local/Programs/Git/mingw64/libexec/git-core/git-credential-manager-core.exe get
info: detecting host provider for 'https://git.my.domain/'...
fatal: parsing "*.my.domain" - Quantifier {x,y} following nothing.

$ echo $?
127

While this succeeds:

$ echo -e "protocol=https\nhost=git.my.domain" | GIT_TRACE=1 NO_PROXY= no_proxy= ~/AppData/Local/Programs/Git/mingw64/libexec/git-core/git-credential-manager-core.exe get
info: detecting host provider for 'https://git.my.domain/'...
protocol=https
host=git.my.domain
username=<redacted>
password=<redacted>

$ echo $?
0

The underlying issue here is that there doesn't appear to be a standard format for NO_PROXY/no_proxy. cURL wants a leading dot instead of a glob (i.e. .my.domain instead of *.my.domain), however cURL also supports * to match all hosts

Most other tools handle an incorrectly formatted NO_PROXY entry gracefully (i.e. by ignoring it) however GCM core is immediately exiting with an error code, and not completing its task of getting/storing the variables.

There's probably a separate question of why GCM core even needs to care about the proxy settings for get/store operations, but the main issue here is that it's aborting when it probably shouldn't.

This is happening in GCM core version 2.0.567+3047faf390 on Windows (bundled with Git for Windows version 2.33)

[mjcheetham]

The underlying issue here is that there doesn't appear to be a standard format for NO_PROXY/no_proxy. cURL wants a leading dot instead of a glob (i.e. .my.domain instead of *.my.domain), however cURL also supports * to match all hosts

Ah yes.. thanks for bring this up. This is why we cannot have nice things(!) 🤷 😆
Hopefully PR #501 and #503 should bring GCM in line with libcurl's behaviour, and therefore Git.

Most other tools handle an incorrectly formatted NO_PROXY entry gracefully (i.e. by ignoring it) however GCM core is immediately exiting with an error code, and not completing its task of getting/storing the variables.

The changes should also catch any problems with proxy setting parsing/configuration and emit a warning only (and not crash).

There's probably a separate question of why GCM core even needs to care about the proxy settings for get/store operations, but the main issue here is that it's aborting when it probably shouldn't.

GCM does more than just store and recall credentials, for the supported host providers because their authentication stacks are more involved, including authority discovery, token refresh, etc.

Now that #501 has been merged, a fix for this should be out in the next release. Watch this space 👀