[BUG] arrays in .npmrc are mangled when set as npm_config_ enironment variables breaking configuration

Is there an existing issue for this?

• I have searched the existing issues

This issue exists in the latest npm version

• I am using the latest npm

Current Behavior

With the following in .npmrc on npm@8.19.1

public-hoist-pattern[] = @react-native-community/cli-platform-android*
public-hoist-pattern[] = @react-native-google-signin/google-signin*

When running a script an environment variable public-hoist-pattern gets set to a mangled multiline string

public-hoist-pattern = "\"@react-native-community/cli-platform-android*\\n\\n@react-native-google-signin/google-signin*\""

This env var overrides any parsing of .npmrc and breaks builds because the array got mangled into a multiline string.

Expected Behavior

Npm does not set npm_config_ environment variables (I couldn't find this docmented anywhere) or at least doesn't mangle the information in .npmrc if it does.

Steps To Reproduce

1. npm install -g npm@8.19.1
2. add an array to .npmrc
3. run any script in package.json that outputs env
4. see the array has been mangled by npm into an undocumented npm_config_ environment variable as a multiline string

Rolling back to npm@7.18.1 fixes the issue as it no longer sets the undocumented environment variables

See related issue on pnpm https://github.com/pnpm/pnpm/issues/5347

Environment

• npm: 8.19.1
• Node.js: 16.17.0
• OS Name: MacOS 12.5.1 arm64
• System Model Name: Macbook Pro 16 M1Pro 2021
• npm config:

; "project" config from /Users/imagio/dev/project/.npmrc

public-hoist-pattern = ["@react-native-community/cli-platform-android*","@react-native-google-signin/google-signin*"]

; node bin location = /Users/imagio/.fnm/node-versions/v16.17.0/installation/bin/node
; node version = v16.17.0
; npm local prefix = /Users/imagio/dev/project
; npm version = 8.19.1
; cwd = /Users/imagio/dev/project
; HOME = /Users/imagio

Reproduce the behavior with npm@8.19.1 using the shown .npmrc array entries and a package.json script that outputs env. Compare the generated npm_config_ environment variable with npm@7.18.1 and verify the array remains intact rather than becoming a mangled multiline string.