magit-commit-oid: New function

Replace `magit-rev-hash' and some uses of `magit-commit-p',
preparing for `magit-commit-p' to return t instead of the oid.

5 files changed, 37 insertions, 22 deletions

diff --git a/lisp/magit-diff.el b/lisp/magit-diff.el
index 6155c79..e6e8859 100644
--- a/lisp/magit-diff.el
+++ b/lisp/magit-diff.el
@@ -1437,8 +1437,8 @@ for a revision."
       (when module
         (setq default-directory
               (expand-file-name (file-name-as-directory module))))
-      (unless (magit-commit-p rev)
-        (user-error "%s is not a commit" rev))
+      (unless (magit-commit-oid rev t)
+        (user-error "%s cannot be dereferenced as a commit" rev))
       (when file
         (save-buffer))
       (let ((buf (magit-revision-setup-buffer rev args files)))
@@ -1931,7 +1931,7 @@ commit or stash at point, then prompt for a commit."
           (setq cmd #'magit-show-commit)
           (setq buf (magit-get-mode-buffer 'magit-revision-mode)))
          (tag
-          (setq rev (magit-rev-hash (oref it value)))
+          (setq rev (magit-commit-oid (oref it value)))
           (setq cmd #'magit-show-commit)
           (setq buf (magit-get-mode-buffer 'magit-revision-mode)))
          (stash
@@ -2760,7 +2760,7 @@ Staging and applying changes is documented in info node
     (magit-buffer-diff-files-suspended nil)))
 
 (defun magit-revision-refresh-buffer ()
-  (setq magit-buffer-revision-oid (magit-rev-hash magit-buffer-revision))
+  (setq magit-buffer-revision-oid (magit-commit-oid magit-buffer-revision))
   (magit-set-header-line-format
    (concat (magit-object-type magit-buffer-revision)
            " "  magit-buffer-revision
diff --git a/lisp/magit-ediff.el b/lisp/magit-ediff.el
index f59520a..c5c4b58 100644
--- a/lisp/magit-ediff.el
+++ b/lisp/magit-ediff.el
@@ -223,12 +223,12 @@ and alternative commands."
   (magit-with-toplevel
     (let* ((dir   (magit-gitdir))
            (revA  (or (magit-name-branch "HEAD")
-                      (magit-commit-p "HEAD")))
+                      (magit-commit-oid "HEAD")))
            (revB  (cl-find-if (##file-exists-p (expand-file-name % dir))
                               '("MERGE_HEAD" "CHERRY_PICK_HEAD" "REVERT_HEAD")))
            (revB  (or (magit-name-branch revB)
-                      (magit-commit-p revB)))
-           (revC  (magit-commit-p (magit-git-string "merge-base" revA revB)))
+                      (magit-commit-oid revB)))
+           (revC  (magit-commit-oid (magit-git-string "merge-base" revA revB)))
            (fileA (magit--rev-file-name file revA revB))
            (fileB (magit--rev-file-name file revB revA))
            (fileC (or (magit--rev-file-name file revC revA)
diff --git a/lisp/magit-git.el b/lisp/magit-git.el
index 4c85532..eb78174 100644
--- a/lisp/magit-git.el
+++ b/lisp/magit-git.el
@@ -1443,14 +1443,23 @@ string \"true\", otherwise return nil."
   (magit-git-string-p "rev-parse" "--verify" rev))
 
 (defun magit-commit-p (rev)
-  "Return full hash for REV if it names an existing commit."
+  "Return commit oid for REV if it can be dereferences as a commit.
+Otherwise return nil.  Use `magit-commit-oid' if you actually need
+the oid; eventually this function will return t instead of the oid."
+  ;; TODO Return t instead of the oid.
   (magit-rev-verify (magit--rev-dereference rev)))
 
-(defalias 'magit-rev-hash #'magit-commit-p)
+(defun magit-commit-oid (rev &optional noerror)
+  "Return commit oid for REV if it can be dereferences as a commit.
+Otherwise signal an error, or return nil, if optional NOERROR is non-nil."
+  (cond ((magit-rev-verify (magit--rev-dereference rev)))
+        (noerror nil)
+        ((error "%s cannot be dereferenced as a commit" rev))))
 
 (defun magit--rev-dereference (rev)
   "Return a rev that forces Git to interpret REV as a commit.
-If REV is nil or has the form \":/TEXT\", return REV itself."
+Do so by appending \"^{commit}\"; see \"--verify\" in git-rev-parse(1).
+However, if REV is nil or has the form \":/TEXT\", return REV itself."
   (cond ((not rev) nil)
         ((string-prefix-p ":/" rev) rev)
         ((concat rev "^{commit}"))))
@@ -1461,8 +1470,8 @@ If REV is nil or has the form \":/TEXT\", return REV itself."
 
 (defun magit-rev-eq (a b)
   "Return t if A and B refer to the same commit."
-  (let ((a (magit-commit-p a))
-        (b (magit-commit-p b)))
+  (let ((a (magit-commit-oid a t))
+        (b (magit-commit-oid b t)))
     (and a b (equal a b))))
 
 (defun magit-rev-ancestor-p (a b)
@@ -2582,12 +2591,12 @@ and this option only controls what face is used.")
   (if (string-match magit-range-re range)
       (magit-bind-match-strings (beg sep end) range
         (and (or beg end)
-             (let ((beg-hash (and beg (magit-rev-hash beg)))
-                   (end-hash (and end (magit-rev-hash end))))
-               (and (or (not beg) beg-hash)
-                    (or (not end) end-hash)
-                    (concat beg-hash sep end-hash)))))
-    (magit-rev-hash range)))
+             (let ((beg-oid (and beg (magit-commit-oid beg)))
+                   (end-oid (and end (magit-commit-oid end))))
+               (and (or (not beg) beg-oid)
+                    (or (not end) end-oid)
+                    (concat beg-oid sep end-oid)))))
+    (magit-commit-oid range)))
 
 (defvar magit-revision-faces
   '(magit-hash
@@ -2641,7 +2650,7 @@ and this option only controls what face is used.")
         (and (not (equal string "@"))
              (or (and (>= (length string) 7)
                       (string-match-p "[a-z]" string)
-                      (magit-commit-p string))
+                      (magit-commit-oid string t))
                  (and (magit-ref-p string)
                       (member (get-text-property (point) 'face)
                               magit-revision-faces)))
@@ -2993,6 +3002,11 @@ out.  Only existing branches can be selected."
 (define-obsolete-function-alias 'magit-rev-verify-commit
   #'magit-commit-p "Magit 4.6.0")
 
+(define-obsolete-function-alias 'magit-rev-hash
+  #'magit-commit-p "Magit 4.6.0"
+  "Return oid for REV if it names an existing commit, nil otherwise.
+Instead use `magit-commit-p' or `magit-commit-oid'.")
+
 (provide 'magit-git)
 ;; Local Variables:
 ;; read-symbol-shorthands: (
diff --git a/lisp/magit-sequence.el b/lisp/magit-sequence.el
index 2a655dd..5d2c437 100644
--- a/lisp/magit-sequence.el
+++ b/lisp/magit-sequence.el
@@ -932,8 +932,9 @@ If no such sequence is in progress, do nothing."
              patch commit)
         (while (and patches (>= i cur))
           (setq patch (pop patches))
-          (setq commit (magit-commit-p
-                        (cadr (split-string (magit-file-line patch)))))
+          (setq commit
+                (magit-commit-oid (cadr (split-string (magit-file-line patch)))
+                                  t))
           (cond ((and commit (= i cur))
                  (magit-sequence-insert-commit
                   "stop" commit 'magit-sequence-stop))
diff --git a/lisp/magit-stash.el b/lisp/magit-stash.el
index d328df0..0327bd0 100644
--- a/lisp/magit-stash.el
+++ b/lisp/magit-stash.el
@@ -631,7 +631,7 @@ See also info node `(magit)Section Movement'."
                        'font-lock-face
                        (list :weight 'normal :foreground
                              (face-attribute 'default :foreground)))))
-  (setq magit-buffer-revision-oid (magit-rev-hash magit-buffer-revision))
+  (setq magit-buffer-revision-oid (magit-commit-oid magit-buffer-revision))
   (magit-insert-section (stash)
     (magit-run-section-hook 'magit-stash-sections-hook)))