[nongnu] elpa/git-commit f8f938352d 5/7: magit-clone-sparse: New command

[ELPA Syncer]

branch: elpa/git-commit
commit f8f938352d71680b533a8cf21dcada0809cdb51a
Author: Kyle Meyer <kyle@kyleam.com>
Commit: Kyle Meyer <kyle@kyleam.com>

    magit-clone-sparse: New command
    
    When the goal is to do a sparse checkout after cloning a repo, it's
    possible to avoid checking out undesired files on the initial clone:
    
      $ git clone --no-checkout ...
      $ git sparse-checkout init --cone
      $ git checkout $BRANCH
    
    Doing that probably isn't very common, so it's tempting to add
    --no-checkout to the magit-clone transient and then let users handle
    the sequence themselves.  However
    
      * it seems unlikely that many people would remember that sequence
    
      * those steps don't work well in Magit because, after the `clone
        --no-checkout` step, refreshing the status buffer will get hung up
        on all the "deleted" files.  That's true even with a repo of
        normal size, but it seems reasonable to expect larger target repos
        in the sparse checkout context.
    
    Add a dedicated command that hooks into magit-clone-internal to enable
    a sparse checkout before a refresh is attempted.
---
 docs/RelNotes/3.4.0.org |  4 ++++
 docs/magit.org          | 11 +++++++++++
 lisp/magit-clone.el     | 19 ++++++++++++++++++-
 3 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/docs/RelNotes/3.4.0.org b/docs/RelNotes/3.4.0.org
index 3572db3b33..86fa3c34de 100644
--- a/docs/RelNotes/3.4.0.org
+++ b/docs/RelNotes/3.4.0.org
@@ -16,6 +16,10 @@
 - New transient ~magit-sparse-checkout~ provides an interface to the
   ~git sparse-checkout~ command, introduced in Git v2.25.  #4102
 
+- New command ~magit-clone-sparse~ makes it possible to clone a
+  repository and then immediately enable a sparse checkout, avoiding a
+  checkout of the full working tree.  #4102
+
 ** Fixes since v3.3.0
 
 - Automatic saving of file-visiting buffers was broken inside remote
diff --git a/docs/magit.org b/docs/magit.org
index a1c766c001..4432e34bfd 100644
--- a/docs/magit.org
+++ b/docs/magit.org
@@ -4141,6 +4141,13 @@ argument is used and on the value of 
~magit-clone-always-transient~.
   By default the depth of the cloned history is a single commit,
   but with a prefix argument the depth is read from the user.
 
+- Key: C > (magit-clone-sparse) ::
+
+  This command creates a clone of an existing repository and
+  initializes a sparse checkout, avoiding a checkout of the full
+  working tree.  To add more directories, use the
+  ~magit-sparse-checkout~ transient (see [[*Sparse checkouts]]).
+
 - Key: C b (magit-clone-bare) ::
 
   This command creates a bare clone of an existing repository.
@@ -7045,6 +7052,10 @@ version.
   This command restores the full checkout.  To return to the previous
   sparse checkout, call ~magit-sparse-checkout-enable~.
 
+A sparse checkout can also be initiated when cloning a repository by
+using the ~magit-clone-sparse~ command in the ~magit-clone~ transient
+(see [[*Cloning Repository]]).
+
 If you want the status buffer to indicate when a sparse checkout is
 enabled, add the function ~magit-sparse-checkout-insert-header~ to
 ~magit-status-headers-hook~.
diff --git a/lisp/magit-clone.el b/lisp/magit-clone.el
index f2813cb88a..91e06ce8d6 100644
--- a/lisp/magit-clone.el
+++ b/lisp/magit-clone.el
@@ -129,6 +129,9 @@ the name of the owner.  Also see `magit-clone-name-alist'."
    ("s" "shallow"            magit-clone-shallow)
    ("d" "shallow since date" magit-clone-shallow-since :level 7)
    ("e" "shallow excluding"  magit-clone-shallow-exclude :level 7)
+   (">" "sparse checkout"    magit-clone-sparse
+    :if (lambda () (magit-git-version>= "2.25.0"))
+    :level 6)
    ("b" "bare"               magit-clone-bare)
    ("m" "mirror"             magit-clone-mirror)]
   (interactive (list (or magit-clone-always-transient current-prefix-arg)))
@@ -193,7 +196,14 @@ Then show the status buffer for the new repository."
   (interactive (magit-clone-read-args))
   (magit-clone-internal repository directory (cons "--mirror" args)))
 
-(defun magit-clone-internal (repository directory args)
+;;;###autoload
+(defun magit-clone-sparse (repository directory args)
+  "Clone REPOSITORY into DIRECTORY and create a sparse checkout."
+  (interactive (magit-clone-read-args))
+  (magit-clone-internal repository directory (cons "--no-checkout" args)
+                        'sparse))
+
+(defun magit-clone-internal (repository directory args &optional sparse)
   (let* ((checkout (not (memq (car args) '("--bare" "--mirror"))))
          (remote (or (transient-arg-value "--origin" args)
                      (magit-get "clone.defaultRemote")
@@ -234,6 +244,13 @@ Then show the status buffer for the new repository."
                (setf (magit-get "remote.pushDefault") remote))
              (unless magit-clone-set-remote-head
                (magit-remote-unset-head remote))))
+         (when (and sparse checkout)
+           (when (magit-git-version< "2.25.0")
+             (user-error
+              "`git sparse-checkout' not available until Git v2.25"))
+           (let ((default-directory directory))
+             (magit-call-git "sparse-checkout" "init" "--cone")
+             (magit-call-git "checkout" (magit-get-current-branch))))
          (with-current-buffer (process-get process 'command-buf)
            (magit-status-setup-buffer directory)))))))