bug#19045: 25.0.50; [PATCH] vc-git-print-log use --follow

[Juri Linkov <juri@linkov.net>]

> Could we use message-truncate-lines and just one message call instead?

Maybe.  But currently what is truncated is not the whole command line,
but each of the command switches.  I don't know how important this is.

> The 20 characters limit seems arbitrary, we just need to avoid resizing the
> echo area. And if the "in background... done" part being truncated is
> a worry, we can rephrase them to go at the beginning of the sentence.

Indeed, truncating "in background... done" is not nice, and I have
no idea how to rephrase it.

Anyway, this is the current patch to try:

diff --git a/lisp/vc/vc-dispatcher.el b/lisp/vc/vc-dispatcher.el
index b0d2221..21f2b98 100644
--- a/lisp/vc/vc-dispatcher.el
+++ b/lisp/vc/vc-dispatcher.el
@@ -290,16 +290,12 @@ vc-do-command
   (let* ((files
 	  (mapcar (lambda (f) (file-relative-name (expand-file-name f)))
 		  (if (listp file-or-list) file-or-list (list file-or-list))))
+	 (message-truncate-lines t)
 	 (full-command
-	  ;; What we're doing here is preparing a version of the command
-	  ;; for display in a debug-progress message.  If it's fewer than
-	  ;; 20 characters display the entire command (without trailing
-	  ;; newline).  Otherwise display the first 20 followed by an ellipsis.
 	  (concat (if (string= (substring command -1) "\n")
 		      (substring command 0 -1)
 		    command)
-		  " "
-		  (vc-delistify (mapcar (lambda (s) (if (> (length s) 20) (concat (substring s 0 2) "...")  s)) flags))
+		  " " (vc-delistify flags)
 		  " " (vc-delistify files))))
     (save-current-buffer
       (unless (or (eq buffer t)
@@ -332,7 +328,8 @@ vc-do-command
 		(setq status proc)
 		(when vc-command-messages
 		  (vc-run-delayed
-		   (message "Running %s in background... done" full-command))))
+		    (let ((message-truncate-lines t))
+		      (message "Running %s in background... done" full-command)))))
 	    ;; Run synchronously
 	    (when vc-command-messages
 	      (message "Running %s in foreground..." full-command))