ProcessLine method returns error when it identifies a mime that contains more than 300 children. MimePart::parse is not handling this error which causes the ProcessLine to log an error for every line of the mime.

This bug was fixed in PECL mailparse-v3.0.3 which was not ported hhvm library.

Bug - https://bugs.php.net/bug.php?id=63542
Fix - php/pecl-mail-mailparse@8aa8c3d

I have tried to simply port these fixes to HHVM.

HHVM Version

$ hhvm --version
HipHop VM 4.0.4 (rel)
Compiler: 1558567803_N
Repo schema: 3db73d7601eff5f54a8e907a42a71f8c7bfae2cb

Operating System and Version

MacOS Mojave 10.14.5

Standalone code, or other way to reproduce the problem

Pass a large email (with more than 300 attachments) to MimePart::parse method.

MimePart::parse(<large file>, <size>)

Actual result

• Generates lots of MIME message too complex errors.
• Full parsed MIME resource is not returned.

Expected result

• Should generate a single MIME message too complex error
• MimePart::parse should return false