piem: Add :gnu-package keyword to piem-inboxes

With the `:gnu-package` keyword, users can configure a string to match
against the X-GNU-PR-PACKAGE email header for the GNU Bug Tracker.

Message-ID: <20230610095858.26982-2-jlicht@fsfe.org>

2 files changed, 11 insertions, 1 deletions

diff --git a/Documentation/piem.texi b/Documentation/piem.texi
index 26962a4..99185d3 100644
--- a/Documentation/piem.texi
+++ b/Documentation/piem.texi
@@ -168,6 +168,12 @@ repository (e.g., if the inbox receives patches for multiple projects,
 or if you use a few dedicated Git worktrees for different types of
 patches), set @code{:coderepo} to a list of locations.
 
+@cindex issue tracking
+@cindex Debbugs, issue tracking system
+When using the Debbugs instance at @uref{https://bugs.gnu.org} to
+retrieve messages, an inbox can mapped to each message by setting
+@code{:gnu-package} for an inbox.
+
 @findex piem-merged-inboxes
 @vindex piem-get-inboxes-from-config
 If you mirror some inboxes locally (e.g., for fast local access or for
diff --git a/piem.el b/piem.el
index 568e91b..cf78d9b 100644
--- a/piem.el
+++ b/piem.el
@@ -83,6 +83,8 @@ list that supports the following properties:
       A URL hosting HTTPS archives.
   :maildir
       A Maildir directory to inject messages into.
+  :gnu-package
+      A GNU Bug Tracker label to match with for the inbox.
 
 Here's an example for the public-inbox project itself:
 
@@ -393,7 +395,9 @@ files."
                   (rx string-start "publicinbox."
                       (group (one-or-more not-newline)) "."
                       (group
-                       (or "address" "coderepo" "listid" "maildir" "url"))
+                       (or "address" "coderepo"
+                           "listid" "maildir"
+                           "url" "gnu-package"))
                       string-end)
                   key)
              (let* ((inbox-name (match-string 1 key))