Suggestion for `getDecodedValue()`: Don't remove comments

[ThomasLandauer]

Message:

Auto-Submitted: =?UTF-8?Q?auto-replied (vacation)?=

• ->getHeader()->getRawValue() gives:

=?UTF-8?Q?auto-replied (vacation)?=

• ->getHeaderValue() gives:

auto-replied (vacation)

• ->getDecodedValue() gives:

auto-replied (vacation)

So the winners are getHeaderValue() or getDecodedValue()

---

But when the header doesn't contain the (unnecessary) encoding:

Auto-Submitted: auto-replied (vacation)

• ->getHeader()->getRawValue() gives:

auto-replied (vacation)

• ->getHeaderValue() gives:

auto-replied

• ->getDecodedValue() gives:

auto-replied

So the winner is getRawValue()

Bottom line: Neither method fits in both situations. So what's the easiest way to get such a method (apart from inventing a new one)?
I think getDecodedValue could be changed to keep the part in parentheses ("comment").

[zbateson]

What you want is a mix of a few things... like a raw but mime decoded but unfolded value... you could take the raw header and run it through the mime decoder, or force the type to be "subject" which will show the comments getHeaderAs('Auto-Submitted', SubjectHeader::class, 0)->getDecodedValue()

[zbateson]

Or you could register your own HeaderFactory that configures Auto-Submitted as a Subject header.

[ThomasLandauer]

OK, this indeed works:

$message->getHeaderAs(HeaderConsts::AUTO_SUBMITTED, SubjectHeader::class)->getDecodedValue()

But it feels a little hacky ;-) How would the other way (manually through the mime decoder) look like? I ended up at AbstractHeader::parseHeaderValue(), but this is protected.

Do you think this should me documented somewhere? Something like:

As per RFCxy, everything inside parentheses are treated as comments any therefore removed (except from Subject). To keep it, use: