Collapse successive char deletions in the undo log

* src/cmds.c (remove_excessive_undo_boundaries): New function,
extracted from Fself_insert_command.
(Fdelete_char, Fself_insert_command): Use it.
* src/fileio.c (Fmake_symbolic_link): Rename arg to `target'.
* src/keyboard.c (syms_of_keyboard): `top-level' shouldn't be special.

3 files changed, 52 insertions, 41 deletions

diff --git a/src/cmds.c b/src/cmds.c
index 270fc39cabc..168ce8355ed 100644
--- a/src/cmds.c
+++ b/src/cmds.c
@@ -213,6 +213,36 @@ to t.  */)
   return Qnil;
 }
 
+static int nonundocount;
+
+static void
+remove_excessive_undo_boundaries (void)
+{
+  bool remove_boundary = true;
+
+  if (!EQ (Vthis_command, KVAR (current_kboard, Vlast_command)))
+    nonundocount = 0;
+
+  if (NILP (Vexecuting_kbd_macro))
+    {
+      if (nonundocount <= 0 || nonundocount >= 20)
+        {
+          remove_boundary = false;
+          nonundocount = 0;
+        }
+      nonundocount++;
+    }
+
+  if (remove_boundary
+      && CONSP (BVAR (current_buffer, undo_list))
+      && NILP (XCAR (BVAR (current_buffer, undo_list)))
+      /* Only remove auto-added boundaries, not boundaries
+         added by explicit calls to undo-boundary.  */
+      && EQ (BVAR (current_buffer, undo_list), last_undo_boundary))
+    /* Remove the undo_boundary that was just pushed.  */
+    bset_undo_list (current_buffer, XCDR (BVAR (current_buffer, undo_list)));
+}
+
 DEFUN ("delete-char", Fdelete_char, Sdelete_char, 1, 2, "p\nP",
        doc: /* Delete the following N characters (previous if N is negative).
 Optional second arg KILLFLAG non-nil means kill instead (save in kill ring).
@@ -227,6 +257,9 @@ because it respects values of `delete-active-region' and `overwrite-mode'.  */)
 
   CHECK_NUMBER (n);
 
+  if (abs (XINT (n)) < 2)
+    remove_excessive_undo_boundaries ();
+
   pos = PT + XINT (n);
   if (NILP (killflag))
     {
@@ -252,8 +285,6 @@ because it respects values of `delete-active-region' and `overwrite-mode'.  */)
   return Qnil;
 }
 
-static int nonundocount;
-
 /* Note that there's code in command_loop_1 which typically avoids
    calling this.  */
 DEFUN ("self-insert-command", Fself_insert_command, Sself_insert_command, 1, 1, "p",
@@ -267,34 +298,13 @@ After insertion, the value of `auto-fill-function' is called if the
 At the end, it runs `post-self-insert-hook'.  */)
   (Lisp_Object n)
 {
-  bool remove_boundary = 1;
   CHECK_NUMBER (n);
 
   if (XFASTINT (n) < 0)
     error ("Negative repetition argument %"pI"d", XFASTINT (n));
 
-  if (!EQ (Vthis_command, KVAR (current_kboard, Vlast_command)))
-    nonundocount = 0;
-
-  if (NILP (Vexecuting_kbd_macro)
-      && !EQ (minibuf_window, selected_window))
-    {
-      if (nonundocount <= 0 || nonundocount >= 20)
-        {
-          remove_boundary = 0;
-          nonundocount = 0;
-        }
-      nonundocount++;
-    }
-
-  if (remove_boundary
-      && CONSP (BVAR (current_buffer, undo_list))
-      && NILP (XCAR (BVAR (current_buffer, undo_list)))
-      /* Only remove auto-added boundaries, not boundaries
-         added be explicit calls to undo-boundary.  */
-      && EQ (BVAR (current_buffer, undo_list), last_undo_boundary))
-    /* Remove the undo_boundary that was just pushed.  */
-    bset_undo_list (current_buffer, XCDR (BVAR (current_buffer, undo_list)));
+  if (XFASTINT (n) < 2)
+    remove_excessive_undo_boundaries ();
 
   /* Barf if the key that invoked this was not a character.  */
   if (!CHARACTERP (last_command_event))
diff --git a/src/fileio.c b/src/fileio.c
index a6e7fbb83d2..796f08d3c58 100644
--- a/src/fileio.c
+++ b/src/fileio.c
@@ -2344,62 +2344,62 @@ This is what happens in interactive use with M-x.  */)
 
 DEFUN ("make-symbolic-link", Fmake_symbolic_link, Smake_symbolic_link, 2, 3,
        "FMake symbolic link to file: \nGMake symbolic link to file %s: \np",
-       doc: /* Make a symbolic link to FILENAME, named LINKNAME.
+       doc: /* Make a symbolic link to TARGET, named LINKNAME.
 Both args must be strings.
 Signals a `file-already-exists' error if a file LINKNAME already exists
 unless optional third argument OK-IF-ALREADY-EXISTS is non-nil.
 A number as third arg means request confirmation if LINKNAME already exists.
 This happens for interactive use with M-x.  */)
-  (Lisp_Object filename, Lisp_Object linkname, Lisp_Object ok_if_already_exists)
+  (Lisp_Object target, Lisp_Object linkname, Lisp_Object ok_if_already_exists)
 {
   Lisp_Object handler;
-  Lisp_Object encoded_filename, encoded_linkname;
+  Lisp_Object encoded_target, encoded_linkname;
   struct gcpro gcpro1, gcpro2, gcpro3, gcpro4;
 
-  GCPRO4 (filename, linkname, encoded_filename, encoded_linkname);
-  encoded_filename = encoded_linkname = Qnil;
-  CHECK_STRING (filename);
+  GCPRO4 (target, linkname, encoded_target, encoded_linkname);
+  encoded_target = encoded_linkname = Qnil;
+  CHECK_STRING (target);
   CHECK_STRING (linkname);
   /* If the link target has a ~, we must expand it to get
      a truly valid file name.  Otherwise, do not expand;
      we want to permit links to relative file names.  */
-  if (SREF (filename, 0) == '~')
-    filename = Fexpand_file_name (filename, Qnil);
+  if (SREF (target, 0) == '~')
+    target = Fexpand_file_name (target, Qnil);
 
   if (!NILP (Ffile_directory_p (linkname)))
-    linkname = Fexpand_file_name (Ffile_name_nondirectory (filename), linkname);
+    linkname = Fexpand_file_name (Ffile_name_nondirectory (target), linkname);
   else
     linkname = Fexpand_file_name (linkname, Qnil);
 
   /* If the file name has special constructs in it,
      call the corresponding file handler.  */
-  handler = Ffind_file_name_handler (filename, Qmake_symbolic_link);
+  handler = Ffind_file_name_handler (target, Qmake_symbolic_link);
   if (!NILP (handler))
-    RETURN_UNGCPRO (call4 (handler, Qmake_symbolic_link, filename,
+    RETURN_UNGCPRO (call4 (handler, Qmake_symbolic_link, target,
                            linkname, ok_if_already_exists));
 
   /* If the new link name has special constructs in it,
      call the corresponding file handler.  */
   handler = Ffind_file_name_handler (linkname, Qmake_symbolic_link);
   if (!NILP (handler))
-    RETURN_UNGCPRO (call4 (handler, Qmake_symbolic_link, filename,
+    RETURN_UNGCPRO (call4 (handler, Qmake_symbolic_link, target,
                            linkname, ok_if_already_exists));
 
-  encoded_filename = ENCODE_FILE (filename);
+  encoded_target = ENCODE_FILE (target);
   encoded_linkname = ENCODE_FILE (linkname);
 
   if (NILP (ok_if_already_exists)
       || INTEGERP (ok_if_already_exists))
     barf_or_query_if_file_exists (linkname, false, "make it a link",
                                   INTEGERP (ok_if_already_exists), false);
-  if (symlink (SSDATA (encoded_filename), SSDATA (encoded_linkname)) < 0)
+  if (symlink (SSDATA (encoded_target), SSDATA (encoded_linkname)) < 0)
     {
       /* If we didn't complain already, silently delete existing file.  */
       int symlink_errno;
       if (errno == EEXIST)
         {
           unlink (SSDATA (encoded_linkname));
-          if (symlink (SSDATA (encoded_filename), SSDATA (encoded_linkname))
+          if (symlink (SSDATA (encoded_target), SSDATA (encoded_linkname))
               >= 0)
             {
               UNGCPRO;
@@ -2414,7 +2414,7 @@ This happens for interactive use with M-x.  */)
         }
 
       symlink_errno = errno;
-      report_file_errno ("Making symbolic link", list2 (filename, linkname),
+      report_file_errno ("Making symbolic link", list2 (target, linkname),
                          symlink_errno);
     }
   UNGCPRO;
diff --git a/src/keyboard.c b/src/keyboard.c
index 2d047da5511..068a47c6c75 100644
--- a/src/keyboard.c
+++ b/src/keyboard.c
@@ -11492,6 +11492,7 @@ for that character after that prefix key.  */);
                doc: /* Form to evaluate when Emacs starts up.
 Useful to set before you dump a modified Emacs.  */);
   Vtop_level = Qnil;
+  XSYMBOL (Qtop_level)->declared_special = false;
 
   DEFVAR_KBOARD ("keyboard-translate-table", Vkeyboard_translate_table,
                  doc: /* Translate table for local keyboard input, or nil.