Files
selfpost/internal/mailhdr/subject.go
T
mix 83c488cc48 release: 0.6.0: Delivery detail page, DNS badge, machine metrics, wide layout
A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
Added:
  - A page per delivery (`/deliveries/{id}`), reached from the *Details* link on
  - A **DNS** badge in the domain list, one per row, carrying the same
  - Machine metrics on the status page: a **Machine** card reporting the
  - An index of the current page's own sections in the navigation column, for the
Changed:
  - Every panel page is laid out in one column of the same width, so moving
  - The mark's small-size variant — the tab icon and the `SP` initials it
  - The stamp's `SELF-HOSTED SMTP RELAY` line is set at 11.5/0.15 instead of
  - The delivery log lists what identifies a message and nothing else: time,
  - Subjects are decoded for display as well as on the way in, so the rows the
  … (4 more in CHANGELOG)

Full detail: CHANGELOG.md (0.6.0).
2026-09-22 15:24:51 +03:00

39 lines
1.6 KiB
Go

// Package mailhdr turns raw mail header values into display text. It sits
// between the journal-milter, which reads headers off the wire, and the panel,
// which shows them: both need the same answer for the same header, and the
// panel needs it for rows the milter wrote before this decoding existed.
package mailhdr
import (
"mime"
"strings"
)
// SubjectMaxRunes caps what the journal keeps of a subject. A Subject header
// may legally run to hundreds of characters; the log only needs enough to
// recognise the message, and the panel shows one row per recipient.
const SubjectMaxRunes = 200
// DecodeSubject turns a raw Subject header into display text. Anything
// non-ASCII arrives as RFC 2047 encoded-words (=?utf-8?Q?=D0=9F…?=), which the
// panel would otherwise show verbatim: unreadable, and — being one unbreakable
// run — wide enough to push the send-log table out of its card. Go's decoder
// covers the UTF-8 and ASCII charsets senders use in practice; for anything
// else (windows-1251, koi8-r) it fails and the raw header is kept, which is no
// worse than not decoding at all. Truncation is applied after decoding so the
// cap counts characters of the subject, not bytes of its encoding.
//
// It is idempotent: already-decoded text contains no encoded-words, so a second
// pass returns it unchanged. That is what lets the panel decode on the way out
// as well as the milter on the way in.
func DecodeSubject(v string) string {
if dec, err := (&mime.WordDecoder{}).DecodeHeader(v); err == nil {
v = dec
}
v = strings.TrimSpace(v)
if r := []rune(v); len(r) > SubjectMaxRunes {
v = string(r[:SubjectMaxRunes]) + "…"
}
return v
}