Add support for sourcehut to bug-reference.el

* lisp/progmodes/bug-reference.el (bug-reference-setup-from-vc-alist):
Add support for bug references like #17 and ~user/project#19 for
sourcehut (sr.ht).
* doc/emacs/maintaining.texi (Bug Reference): Document sourcehut
support.

1 files changed, 25 insertions, 0 deletions

diff --git a/lisp/progmodes/bug-reference.el b/lisp/progmodes/bug-reference.el
index 61d722f5b9d..918930a8afb 100644
--- a/lisp/progmodes/bug-reference.el
+++ b/lisp/progmodes/bug-reference.el
@@ -201,6 +201,31 @@ The second subexpression should match the bug reference (usually a number)."
                     (if (string= (match-string 3) "#")
                         "issues/"
                       "merge_requests/")
+                    (match-string 2))))))
+
+    ;;
+    ;; Sourcehut projects.
+    ;;
+    ;; #19 is an issue.  Other project's issues can be referenced as
+    ;; #~user/project#19.
+    ;;
+    ;; Caveat: The code assumes that a project on git.sr.ht or
+    ;; hg.sr.ht has a tracker of the same name on todo.sh.ht.  That's
+    ;; a very common setup but all sr.ht services are loosely coupled,
+    ;; so you can have a repo without tracker, or a repo with a
+    ;; tracker using a different name, etc.  So we can only try to
+    ;; make a good guess.
+    ("[/@]\\(?:git\\|hg\\).sr.ht[/:]\\(~[.A-Za-z0-9_/-]+\\)"
+     "\\(~[.A-Za-z0-9_/-]+\\)?\\(?:#\\)\\([0-9]+\\)\\>"
+     ,(lambda (groups)
+        (let ((ns-project (nth 1 groups)))
+          (lambda ()
+            (concat "https://todo.sr.ht/"
+                    (or
+                     ;; Explicit user/proj#18 link.
+                     (match-string 1)
+                     ns-project)
+                    "/"
                     (match-string 2)))))))
   "An alist for setting up `bug-reference-mode' based on VC URL.