fix: decode keys that are quoted because they contain =

[MildlyMeticulous]

What / Why

encode() and decode() disagree about keys that contain =, so stringify → parse silently corrupts both the key and the value.

safe() already knows such a key needs quoting:

const safe = val => {
  if (typeof val !== 'string' || val.match(/[=\r\n]/) || ...) {
    return JSON.stringify(val)
  }
  ...
}

But decode() matches the key with [^=]+, which cannot cross the quotes:

const re = /^\[([^\]]*)\]\s*$|^([^=]+)(=(.*))?$/i

So the = inside the quoted key is taken as the separator.

Steps to Reproduce

const ini = require('ini')

const obj = { 'a=b': 'c' }
const text = ini.stringify(obj)   // '"a=b"=c\n'   <- correctly quoted
ini.parse(text)

Expected: { 'a=b': 'c' }
Actual: { '"a': 'b"=c' }

Same for any key containing =:

input	stringify	parse of that
{ 'a=b': 'c' }	"a=b"=c	{ '"a': 'b"=c' }
{ 'key=with=eq': 'v' }	"key=with=eq"=v	{ '"key': 'with=eq"=v' }
{ '=lead': 'v' }	"=lead"=v	{ '"': 'lead"=v' }
{ 'tr=': 'v' }	"tr="=v	{ '"tr': '"=v' }

Keys containing = are not hypothetical — Windows registry exports, connection strings and PATH-style entries all produce them, and #96 is the section-header form of the same root cause.

The fix

Add a fully-quoted string as a first alternative for the key, keeping the group numbering unchanged:

const re = /^\[([^\]]*)\]\s*$|^("(?:\.|[^"\])*"\s*|[^=]+)(=(.*))?$/i

unsafe() already strips the quotes and JSON.parses the result, so nothing else changes.

Because the quoted alternative requires a closing quote, an unterminated quote falls through to [^=]+ and behaves exactly as before — '"a=b' still parses to { '"a': 'b' }. Unquoted keys are untouched: a=b=c still gives { a: 'b=c' }.

Verification

• test/quoted-keys.js added: round-trip cases, the nested-section case, the unquoted-key case, and the unterminated-quote case.
• Against the unpatched lib/ini.js the new file produces 12 failing assertions; with the fix all pass.
• Full suite green (6/6 files), branch + statement + function + line coverage still 100%, npm run lint clean.