Repair pdbtrack so it follows transition from one remote file to another.

* python.el (python-pdbtrack-set-tracked-buffer).

2 files changed, 15 insertions, 4 deletions

diff --git a/lisp/ChangeLog.17 b/lisp/ChangeLog.17
index a40f8f3d67a..224e2a6da7f 100644
--- a/lisp/ChangeLog.17
+++ b/lisp/ChangeLog.17
@@ -1,3 +1,8 @@
+2015-09-20  Ken Manheimer  <ken.manheimer@gmail.com>
+
+        * python.el (python-pdbtrack-set-tracked-buffer): Repair pdbtrack
+        so it follows transition from one remote file to another.
+
 2015-04-06  Alan Mackenzie  <acm@muc.de>
 
         Fix miscellaneous glitches in cc-mode.el.  (Bug#20245)
diff --git a/lisp/progmodes/python.el b/lisp/progmodes/python.el
index 9528ffeebbc..243125e310c 100644
--- a/lisp/progmodes/python.el
+++ b/lisp/progmodes/python.el
@@ -3635,12 +3635,18 @@ Never set this variable directly, use
   "Set the buffer for FILE-NAME as the tracked buffer.
 Internally it uses the `python-pdbtrack-tracked-buffer' variable.
 Returns the tracked buffer."
-  (let ((file-buffer (get-file-buffer
-                      (concat (file-remote-p default-directory)
-                              file-name))))
+  (let* ((file-name-prospect (concat (file-remote-p default-directory)
+                              file-name))
+         (file-buffer (get-file-buffer file-name-prospect)))
     (if file-buffer
         (setq python-pdbtrack-tracked-buffer file-buffer)
-      (setq file-buffer (find-file-noselect file-name))
+      (cond
+       ((file-exists-p file-name-prospect)
+        (setq file-buffer (find-file-noselect file-name-prospect)))
+       ((and (not (equal file-name file-name-prospect))
+             (file-exists-p file-name))
+        ;; Fallback to a locally available copy of the file.
+        (setq file-buffer (find-file-noselect file-name-prospect))))
       (when (not (member file-buffer python-pdbtrack-buffers-to-kill))
         (add-to-list 'python-pdbtrack-buffers-to-kill file-buffer)))
     file-buffer))