bug#69584: 29.2.50; project-find-functions should have access to maybe-prompt

[Spencer Baugh <sbaugh@janestreet.com>]

I'd like to write a project-find-function which might prompt when
called, and so to suppress that prompting I'd like to be able to check
the maybe-prompt argument that project-current received.

Possible new functions for project-find-functions which would benefit
from this:

- A local project-find-function in a version control buffer for viewing
a branch log; if the branch is not currently checked out, prompt to
check out that branch (or create a worktree for it) before returning the
project

- A local project-find-function in a buffer from a package for Git
forges; if the buffer corresponds to a repository which is not currently
cloned locally, prompt to clone the repository.

These behaviors should of course be suppressed if maybe-prompt is nil,
which is why it would be nice to be able to access maybe-prompt.

Since adding a new argument to project-find-functions is hard, maybe we
could do this by introducing a new dynamic variable
project-find-functions-may-prompt which we let-bind?  Like:

diff --git a/lisp/progmodes/project.el b/lisp/progmodes/project.el
index c7c07c3d34c..3975182b88d 100644
--- a/lisp/progmodes/project.el
+++ b/lisp/progmodes/project.el
@@ -242,8 +242,9 @@ project-current
         (setq pr (cons 'transient directory))))
     pr))
 
-(defun project--find-in-directory (dir)
-  (run-hook-with-args-until-success 'project-find-functions dir))
+(defun project--find-in-directory (dir &optional maybe-prompt)
+  (let ((project-find-functions-may-prompt maybe-prompt))
+    (run-hook-with-args-until-success 'project-find-functions dir)))
 
 (defvar project--within-roots-fallback nil)
 


In GNU Emacs 29.2.50 (build 4, x86_64-pc-linux-gnu, X toolkit, cairo
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