bug#21454: 25.1.50; `parse-colon-path' fails with file names containing multiple consecutive "/"

[Tino Calancha <tino.calancha@gmail.com>]

A new patch handling multiple "/" in front of a dir as it was
done before: collapse multiple "/" in front of the directory.

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From c363eee16029566be565ef37bec7952fdb630bb1 Mon Sep 17 00:00:00 2001
From: Tino Calancha <tino.calancha@gmail.com>
Date: Tue, 13 Sep 2016 17:40:55 +0900
Subject: [PATCH] parse-colon-path:  Handle a dir with 2 consecutive dir
  separator

Do not truncate /foo//bar to /bar/
* lisp/files.el (parse-colon-path): Use substitute-env-vars and
expand-file-name instead of substitute-in-file-name (Bug#21454).
---
  lisp/files.el | 15 +++++++++++----
  1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/lisp/files.el b/lisp/files.el
index 4bd708d..79e5abf 100644
--- a/lisp/files.el
+++ b/lisp/files.el
@@ -672,10 +672,17 @@ parse-colon-path
  a leading or trailing separator, or two adjacent separators), return
  nil (meaning `default-directory') as the associated list element."
    (when (stringp search-path)
-    (mapcar (lambda (f)
-	      (if (equal "" f) nil
-		(substitute-in-file-name (file-name-as-directory f))))
-	    (split-string search-path path-separator))))
+    (let ((spath (substitute-env-vars search-path)))
+      (mapcar (lambda (f)
+                (if (equal "" f) nil
+                  (let ((dir (expand-file-name (file-name-as-directory 
f))))
+                    ;; Previous implementation used 
`substitute-in-file-name'
+                    ;; which collapse multiple "/" in front.  Do the same 
for
+                    ;; backward compatibility.
+                    (while (and (char-equal ?/ (aref dir 0))
+                                (char-equal ?/ (aref dir 1)))
+                      (setq dir (substring dir 1))) dir)))
+              (split-string spath path-separator)))))

  (defun cd-absolute (dir)
    "Change current directory to given absolute file name DIR."
-- 
2.9.3

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In GNU Emacs 25.1.50.1 (x86_64-pc-linux-gnu, GTK+ Version 3.21.5)
  of 2016-09-13
Repository revision: ead76c4603f2c4a1761ab8a7dd5cf6f56e782fb2