magit-copy-revision-abbreviated: New option

magit-copy-buffer-revision, and magit-copy-section-value when
appropriate, pushes the full revision hash to magit-revision-stack and
the kill ring.  If callers would like to use this to insert an
abbreviated hash, their main options are either to
(1) yank the full hash and truncate it manually or (2) configure
magit-pop-revision-stack-format accordingly and call
magit-pop-revision-stack.

Offer an option to put the abbreviated hash on the kill ring and the
magit-revision-stack.

Documentation/RelNotes/2.91.0.org

@@ -308,6 +308,8 @@
 - Commands under the ~magit-gitignore~ prefix now include directories
   that contain only untracked files as completion candidates.  #3985
 
+- Added new option ~magit-copy-revision-abbreviated~.  #4014
+
 ** Fixes since v2.90.0
 
 - Bumped the minimal required version of ~git-commit~ to the correct

lisp/magit-extras.el

@@ -463,6 +463,12 @@ that)."
                (choice (regexp :tag "Find index regexp")
                        (const :tag "Don't number entries" nil))))
 
+(defcustom magit-copy-revision-abbreviated nil
+  "Whether to save abbreviated revision to `kill-ring' and `magit-revision-stack'."
+  :package-version '(magit . "2.91.0")
+  :group 'magit-miscellaneous
+  :type 'boolean)
+
 ;;;###autoload
 (defun magit-pop-revision-stack (rev toplevel)
   "Insert a representation of a revision into the current buffer.
@@ -552,6 +558,10 @@ the current section is a commit, branch, or tag section, push
 the (referenced) revision to the `magit-revision-stack' for use
 with `magit-pop-revision-stack'.
 
+When `magit-copy-revision-abbreviated' is non-nil, save the
+abbreviated revision to the `kill-ring' and the
+`magit-revision-stack'.
+
 When the current section is a branch or a tag, and a prefix
 argument is used, then save the revision at its tip to the
 `kill-ring' instead of the reference name.
@@ -586,7 +596,9 @@ hunk, strip the outer diff marker column."
                     (file-name-as-directory
                      (expand-file-name (magit-section-parent-value section)
                                        (magit-toplevel))))))
-           (setq value (magit-rev-parse value))
+           (setq value (magit-rev-parse
+                        (and magit-copy-revision-abbreviated "--short")
+                        value))
            (push (list value default-directory) magit-revision-stack)
            (kill-new (message "%s" (or (and current-prefix-arg ref)
                                        value)))))
@@ -613,7 +625,11 @@ the current section instead, using `magit-copy-section-value'.
 
 When the region is active, then save that to the `kill-ring',
 like `kill-ring-save' would, instead of behaving as described
-above."
+above.
+
+When `magit-copy-revision-abbreviated' is non-nil, save the
+abbreviated revision to the `kill-ring' and the
+`magit-revision-stack'."
   (interactive)
   (if (use-region-p)
       (call-interactively #'copy-region-as-kill)
@@ -626,7 +642,9 @@ above."
                              magit-buffer-range))
                           (magit-status-mode "HEAD")))))
       (when (magit-commit-p rev)
-        (setq rev (magit-rev-parse rev))
+        (setq rev (magit-rev-parse
+                   (and magit-copy-revision-abbreviated "--short")
+                   rev))
         (push (list rev default-directory) magit-revision-stack)
         (kill-new (message "%s" rev))))))