[elpa] externals/vlf 0610822 046/310: Make saving with change of size correct.

[Stefan Monnier]

branch: externals/vlf
commit 06108220e20e381dbcab4dda507d37dfb2b9abf1
Author: Andrey Kotlarski <m00naticus@gmail.com>
Commit: Andrey Kotlarski <m00naticus@gmail.com>

    Make saving with change of size correct.
---
 vlfi.el | 32 +++++++++++++++++++++++++-------
 1 file changed, 25 insertions(+), 7 deletions(-)

diff --git a/vlfi.el b/vlfi.el
index ffa5263..db15580 100644
--- a/vlfi.el
+++ b/vlfi.el
@@ -399,14 +399,32 @@ successful.  Return nil if nothing found."
 or \\[vlfi-discard-edit] to discard changes.")))
 
 (defun vlfi-write ()
-  "Write current chunk to file.  May overwrite existing content."
+  "Write current chunk to file.
+If changing size of chunk, may load the remaining part of file first."
   (interactive)
-  (when (or (= (buffer-size) (- vlfi-end-pos vlfi-start-pos))
-            (y-or-n-p "Changed size of original chunk.  \
-End of chunk will be garbled.  Continue? "))
-    (write-region nil nil buffer-file-name vlfi-start-pos)
-    (vlfi-move-to-chunk vlfi-start-pos vlfi-end-pos)
-    (vlfi-mode))
+  (let ((size-change (- vlfi-end-pos vlfi-start-pos (buffer-size))))
+    (cond ((zerop size-change)
+           (write-region nil nil buffer-file-name vlfi-start-pos t)
+           (vlfi-move-to-chunk vlfi-start-pos vlfi-end-pos)
+           (vlfi-mode))
+          ((y-or-n-p "Changed size of original chunk.  \
+Remaining part of the file has to be loaded.  Continue? ")
+           (let ((pos (point)))
+             (goto-char (point-max))
+             (setq vlfi-file-size
+                   (nth 7 (file-attributes buffer-file-name)))
+             (let ((load-reporter (make-progress-reporter
+                                   "Loading rest of the file")))
+               (insert-file-contents buffer-file-name nil
+                                     vlfi-end-pos vlfi-file-size)
+               (when (< 0 size-change)  ; pad with empty characters
+                 (goto-char (point-max))
+                 (insert-char 32 size-change))
+               (progress-reporter-done load-reporter))
+             (write-region nil nil buffer-file-name vlfi-start-pos t)
+             (vlfi-move-to-chunk vlfi-start-pos vlfi-end-pos)
+             (goto-char pos))
+           (vlfi-mode))))
   t)
 
 (defun vlfi-discard-edit ()