[nongnu] elpa/annotate b22f594f3b 336/372: Merge pull request #107 from cage2/prevent-saving-empty-db

[ELPA Syncer]

branch: elpa/annotate
commit b22f594f3b813b12e442860344d2feb39d944b53
Merge: bd12129213 641daae9d0
Author: cage2 <1257703+cage2@users.noreply.github.com>
Commit: GitHub <noreply@github.com>

    Merge pull request #107 from cage2/prevent-saving-empty-db
    
    Prevented saving a file with an empty database;
---
 Changelog   |  8 +++++++-
 NEWS.org    | 12 ++++++++++++
 README.org  |  8 ++++++--
 annotate.el | 48 ++++++++++++++++++++++++++++++++++--------------
 4 files changed, 59 insertions(+), 17 deletions(-)

diff --git a/Changelog b/Changelog
index e7434ad668..33999c0519 100644
--- a/Changelog
+++ b/Changelog
@@ -1,4 +1,10 @@
-021-04-30  cage
+2021-05-07  cage
+
+        * annotate.el:
+
+       - prevented saving a file with an empty database;
+
+2021-04-30  cage
 
         * annotate.el:
 
diff --git a/NEWS.org b/NEWS.org
index eb3d0be647..3e9c0eb0dc 100644
--- a/NEWS.org
+++ b/NEWS.org
@@ -231,3 +231,15 @@
 
   This version fixes a bug that prevented command like
   'comment-region' to works properly when annotate-mode was active.
+
+- 2021-05-07 V1.3.0 cage ::
+
+  This version  added a procedure to  prevent an empty database  to be
+  saved on the user's disk.
+
+  Moreover if an  empty annotations database is going  to overwrite an
+  existing stale database file on disk the file is deleted instead.
+
+  Before  deleting the  old database  file a  confirmation message  is
+  printed    on    the    minibuffer   if    the    custom    variable
+  'annotate-database-confirm-deletion' is non nil (default: t).
diff --git a/README.org b/README.org
index f9e8c65931..eabe5b8ec6 100644
--- a/README.org
+++ b/README.org
@@ -53,15 +53,19 @@ see:
 [[https://github.com/bastibe/annotate.el/issues/68][this thread]] and, in 
particular
 
[[https://github.com/bastibe/annotate.el/issues/68#issuecomment-728218022][this 
message]].
 
+If an  empty annotation database  (in memory) is saved  the database
+file  is deleted  instead, if  ~annotate-database-confirm-deletion~ is
+non  nil (the  default) a  confirmation action  is asked  to the  user
+before actually remove the file from the file system.
+
 Users of
 [[https://github.com/emacscollective/no-littering][no-littering]]
 can take advantage of its packages generated files management.
 
 **** related customizable variable
      - ~annotate-file~
-
-**** related customizable variable
      - ~annotate-warn-if-hash-mismatch~
+     - ~annotate-database-confirm-deletion~
 
 ** keybindings
 
diff --git a/annotate.el b/annotate.el
index 6ff3fc2ad1..2295d2b19a 100644
--- a/annotate.el
+++ b/annotate.el
@@ -7,7 +7,7 @@
 ;; Maintainer: Bastian Bechtold
 ;; URL: https://github.com/bastibe/annotate.el
 ;; Created: 2015-06-10
-;; Version: 1.2.1
+;; Version: 1.3.0
 
 ;; This file is NOT part of GNU Emacs.
 
@@ -58,7 +58,7 @@
 ;;;###autoload
 (defgroup annotate nil
   "Annotate files without changing them."
-  :version "1.2.1"
+  :version "1.3.0"
   :group 'text)
 
 ;;;###autoload
@@ -155,6 +155,13 @@ database is not filtered at all."
   :type 'boolean
   :group 'annotate)
 
+(defcustom annotate-database-confirm-deletion t
+ "If non nil a prompt asking confirmation before deleting a
+database file that is going to be empty after saving an annotated
+file will be shown"
+  :type 'boolean
+  :group 'annotate)
+
 (defcustom annotate-annotation-max-size-not-place-new-line 15
  "The maximum `string-width` allowed for an annotation to be
  placed on the right margin of the window instead of its own line
@@ -1565,19 +1572,32 @@ annotation."
         (ignore-errors (%load-annotation-data))
       (%load-annotation-data))))
 
-(defun annotate-dump-annotation-data (data)
+(defun annotate-dump-annotation-data (data &optional save-empty-db)
   "Save `data` into annotation file."
-  (with-temp-file annotate-file
-    (let* ((print-length nil)
-           (%abbreviate-filename (lambda (record)
-                                   (let ((full-filename 
(annotate-filename-from-dump    record))
-                                         (annotations   
(annotate-annotations-from-dump record))
-                                         (file-checksum 
(annotate-checksum-from-dump    record)))
-                                     (annotate-make-record 
(abbreviate-file-name full-filename)
-                                                           annotations
-                                                           file-checksum))))
-           (actual-data (mapcar %abbreviate-filename data)))
-      (prin1 actual-data (current-buffer)))))
+  (if (or save-empty-db
+          data)
+      (with-temp-file annotate-file
+        (let* ((print-length nil)
+               (%abbreviate-filename (lambda (record)
+                                       (let ((full-filename 
(annotate-filename-from-dump    record))
+                                             (annotations   
(annotate-annotations-from-dump record))
+                                             (file-checksum 
(annotate-checksum-from-dump    record)))
+                                         (annotate-make-record 
(abbreviate-file-name full-filename)
+                                                               annotations
+                                                               
file-checksum))))
+               (actual-data (mapcar %abbreviate-filename data)))
+          (prin1 actual-data (current-buffer))))
+    (let* ((confirm-message    "Delete annotations database file %S? [y/N] ")
+           (delete-confirmed-p (or (not annotate-database-confirm-deletion)
+                                   (string= (read-from-minibuffer (format 
confirm-message
+                                                                           
annotate-file))
+                                            "y"))))
+      (if delete-confirmed-p
+          (condition-case err
+              (delete-file annotate-file t)
+            (error (message "error removing annotation database: %S"
+                            (error-message-string err))))
+        (annotate-dump-annotation-data data t)))))
 
 (cl-defmacro with-matching-annotation-fns ((filename
                                             beginning