Improve performance for rename-file etc.

Although this does not fix Bug#27986, it is a step forward.
I plan to propose a more-significant patch later.
* lisp/files.el (directory-name-p): Move from here ...
* src/fileio.c (Fdirectory_name_p): ... to here.
(directory_like, cp_like_target): New static functions.
(Fcopy_file, Frename_file, Fadd_name_to_file)
(Fmake_symbolic_link):
Use them, to avoid directory-testing syscalls on file names that
must be directories if they exist.  Omit unnecessary
initializations and CHECK_STRING calls.
(Frename_file): Don't call file_name_case_insensitive_p
twice on the same file.  Compare both file names expanded, instead
of the old name expanded and the new one unexpanded.

1 files changed, 0 insertions, 10 deletions

diff --git a/lisp/files.el b/lisp/files.el
index f2758ab18ca..0fe7f9c522a 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -792,16 +792,6 @@ The path separator is colon in GNU and GNU-like systems."
                     (lambda (f) (and (file-directory-p f) 'dir-ok)))
        (error "No such directory found via CDPATH environment variable"))))
 
-(defsubst directory-name-p (name)
-  "Return non-nil if NAME ends with a directory separator character."
-  (let ((len (length name))
-        (lastc ?.))
-    (if (> len 0)
-        (setq lastc (aref name (1- len))))
-    (or (= lastc ?/)
-        (and (memq system-type '(windows-nt ms-dos))
-             (= lastc ?\\)))))
-
 (defun directory-files-recursively (dir regexp &optional include-directories)
   "Return list of all files under DIR that have file names matching REGEXP.
 This function works recursively.  Files are returned in \"depth first\"