https://gitlab.synchro.net/main/sbbs/-/commit/2b8e4cf5aaecfb834c50772f
Modified Files:
src/smblib/smbtxt.c
Log Message:
smblib: decode MIME attachments in nested multipart messages

The boundary= parameter value was terminated only by ';' or a closing
quote, never by the end of the header line. That is harmless for the
top-level Content-Type, which comes from a NUL-terminated header field,
but a nested part's Content-Type is a pointer into the raw message body:
when boundary= is the last parameter on its folded line - what iOS Mail
emits - every following header and body byte was swallowed into the
boundary string, so no delimiter ever matched.

Nested parts therefore yielded no attachments at all, and
smb_getplaintext() could fail on the same messages, leaving the Terminal
Server to display the entire raw MIME body - base64 and all - instead of
the readable text.

Terminate the value at the end of the header line as well, and bound the boundary= search to the part's own (possibly folded) Content-Type field:
once CRLF terminates a value, an unbounded search would otherwise pick up
a boundary= appearing later in the message text. Reject an empty
boundary, which yields the string "--" and so matches the leading dashes
of every delimiter as well as any "--" in the body. Also skip the white
space RFC822 permits around the '=', and end an unquoted value at white
space, which an RFC2046 boundary token cannot contain.

GitLab #1205

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
--- SBBSecho 3.37-Linux
* Origin: Vertrauen - [vert/cvs/bbs].synchro.net (1:103/705)