Re: suggested new command `picture-mouse-set-point'

[Juanma Barranquero <lektu@terra.es>]

On Mon, 28 Oct 2002 22:02:02 -0500, Richard Stallman <rms@gnu.org> wrote:

> The find-file functions will simply use that buffer, so this issue
> does not apply to them.  It does apply to insert-file-literally.

OK.

The following patch implements the functionality for `insert-file' and
`insert-file-literally'.

Before commiting it, three questions/issues:

 - I've made it to ask before inserting, instead of blindingly inserting
*and* issuing a warning.  Which way is preferred?

 - As implemented, it only warns about the first modified buffer visiting
the file, even if there are more.  It seems a bit ugly to show many
buffers in the question, and, OTOH, I'd bet is not very usual to have
multiple modified buffers visiting the very same file.

 - I've extracted code from `find-buffer-visiting' into an internal
`find-buffer-visiting-1' because it already has a lot of good logic to
detect when a file is being visited.  Basically I've added it a
predicate so I can search for a file visited *and* modified.
`find-buffer-visiting' calls the internal one and its interface is not
modified in any way.

Comments?

                                                           /L/e/k/t/u



Index: files.el
===================================================================
RCS file: /cvs/emacs/lisp/files.el,v
retrieving revision 1.620
diff -u -2 -r1.620 files.el
--- files.el	26 Oct 2002 22:34:14 -0000	1.620
+++ files.el	29 Oct 2002 17:55:36 -0000
@@ -1048,4 +1048,36 @@
   :group 'find-file)
 
+(defun find-buffer-visiting-1 (truename &optional predicate)
+  (or (let ((list (buffer-list)) found)
+        (while (and (not found) list)
+          (save-excursion
+            (set-buffer (car list))
+            (if (and buffer-file-name
+                     (string= buffer-file-truename truename)
+                     (or (not predicate)
+                         (funcall predicate (current-buffer))))
+                (setq found (car list))))
+          (setq list (cdr list)))
+        found)
+      (let* ((attributes (file-attributes truename))
+             (number (nthcdr 10 attributes))
+             (list (buffer-list)) found)
+        (and buffer-file-numbers-unique
+             number
+             (while (and (not found) list)
+               (with-current-buffer (car list)
+                 (if (and buffer-file-name
+                          (equal buffer-file-number number)
+                          ;; Verify this buffer's file number
+                          ;; still belongs to its file.
+                          (file-exists-p buffer-file-name)
+                          (equal (file-attributes buffer-file-truename)
+                                 attributes)
+                          (or (not predicate)
+                              (funcall predicate (current-buffer))))
+                     (setq found (car list))))
+               (setq list (cdr list))))
+        found)))
+
 (defun find-buffer-visiting (filename)
   "Return the buffer visiting file FILENAME (a string).
@@ -1056,30 +1088,5 @@
 	(truename (abbreviate-file-name (file-truename filename))))
     (or buf
-	(let ((list (buffer-list)) found)
-	  (while (and (not found) list)
-	    (save-excursion
-	      (set-buffer (car list))
-	      (if (and buffer-file-name
-		       (string= buffer-file-truename truename))
-		  (setq found (car list))))
-	    (setq list (cdr list)))
-	  found)
-	(let* ((attributes (file-attributes truename))
-	       (number (nthcdr 10 attributes))
-	       (list (buffer-list)) found)
-	  (and buffer-file-numbers-unique
-	       number
-	       (while (and (not found) list)
-		 (with-current-buffer (car list)
-		   (if (and buffer-file-name
-			    (equal buffer-file-number number)
-			    ;; Verify this buffer's file number
-			    ;; still belongs to its file.
-			    (file-exists-p buffer-file-name)
-			    (equal (file-attributes buffer-file-truename)
-				   attributes))
-		       (setq found (car list))))
-		 (setq list (cdr list))))
-	  found))))
+        (find-buffer-visiting-1 truename))))
 \f
 (defcustom find-file-wildcards t
@@ -1336,4 +1343,16 @@
 	(fmakunbound 'find-buffer-file-type)))))
 
+(defun insert-file-1 (filename insert-func)
+  (if (file-directory-p filename)
+      (signal 'file-error (list "Opening input file" "file is a directory"
+                                filename)))
+  (let ((buffer (find-buffer-visiting-1 (abbreviate-file-name (file-truename filename))
+                                        #'buffer-modified-p)))
+    (when (or (not buffer)
+              (yes-or-no-p (format "File %s already visited and modified in buffer %s.  Insert? "
+                                   filename (buffer-name buffer))))
+      (let ((tem (funcall insert-func filename)))
+        (push-mark (+ (point) (car (cdr tem))))))))
+
 (defun insert-file-literally (filename)
   "Insert contents of file FILENAME into buffer after point with no conversion.
@@ -1343,9 +1362,5 @@
 \(Its calling sequence is different; see its documentation)."
   (interactive "*fInsert file literally: ")
-  (if (file-directory-p filename)
-      (signal 'file-error (list "Opening input file" "file is a directory"
-				filename)))
-  (let ((tem (insert-file-contents-literally filename)))
-    (push-mark (+ (point) (car (cdr tem))))))
+  (insert-file-1 filename #'insert-file-contents-literally))
 
 (defvar find-file-literally nil
@@ -3148,9 +3163,5 @@
 \(Its calling sequence is different; see its documentation)."
   (interactive "*fInsert file: ")
-  (if (file-directory-p filename)
-      (signal 'file-error (list "Opening input file" "file is a directory"
-				filename)))
-  (let ((tem (insert-file-contents filename)))
-    (push-mark (+ (point) (car (cdr tem))))))
+  (insert-file-1 filename #'insert-file-contents))
 
 (defun append-to-file (start end filename)