* lisp/vc/add-log.el (add-log-file-name): Don't get confused by symlinks.

2 files changed, 28 insertions, 15 deletions

diff --git a/lisp/ChangeLog b/lisp/ChangeLog
index b717877dcf5..db5bc124626 100644
--- a/lisp/ChangeLog
+++ b/lisp/ChangeLog
@@ -1,3 +1,7 @@
+2010-08-21  Stefan Monnier  <monnier@iro.umontreal.ca>
+
+        * vc/add-log.el (add-log-file-name): Don't get confused by symlinks.
+
 2010-08-21  Chong Yidong  <cyd@stupidchicken.com>
 
         * mouse.el (mouse-save-then-kill): Don't save region to kill ring
@@ -10,19 +14,18 @@
 2010-08-21  Vinicius Jose Latorre  <viniciusjl@ig.com.br>
 
         * whitespace.el: Fix slow cursor movement.  Reported by Christoph
-        Groth <cwg@falma.de> and Liu Xin <x_liu@neusoft.com>.  New version
-        13.0.
+        Groth <cwg@falma.de> and Liu Xin <x_liu@neusoft.com>.
+        New version 13.0.
         (whitespace-empty-at-bob-regexp, whitespace-empty-at-eob-regexp):
         Adjust initialization.
         (whitespace-bob-marker, whitespace-eob-marker)
         (whitespace-buffer-changed): New vars.
         (whitespace-cleanup, whitespace-color-on, whitespace-color-off)
         (whitespace-empty-at-bob-regexp, whitespace-empty-at-eob-regexp)
-        (whitespace-post-command-hook, whitespace-display-char-on): Adjust
-        code.
+        (whitespace-post-command-hook, whitespace-display-char-on):
+        Adjust code.
         (whitespace-looking-back, whitespace-buffer-changed): New funs.
-        (whitespace-space-regexp, whitespace-tab-regexp): Eliminated
-        funs.
+        (whitespace-space-regexp, whitespace-tab-regexp): Eliminate funs.
 
 2010-08-19  Stefan Monnier  <monnier@iro.umontreal.ca>
 
@@ -3227,7 +3230,8 @@
         * minibuffer.el (tags-completion-at-point-function): New function.
         (completion-at-point-functions): Use it.
 
-        * cedet/semantic.el (semantic-completion-at-point-function): New function.
+        * cedet/semantic.el (semantic-completion-at-point-function):
+        New function.
         (semantic-mode): Use semantic-completion-at-point-function for
         completion-at-point-functions instead.
 
@@ -3277,8 +3281,8 @@
 
 2010-04-28  Chong Yidong  <cyd@stupidchicken.com>
 
-        * progmodes/bug-reference.el (bug-reference-url-format): Revert
-        2010-04-27 change due to security risk.
+        * progmodes/bug-reference.el (bug-reference-url-format):
+        Revert 2010-04-27 change due to security risk.
 
 2010-04-28  Stefan Monnier  <monnier@iro.umontreal.ca>
 
@@ -3453,8 +3457,7 @@
 
         * ido.el (ido-init-completion-maps): For ido-switch-buffer, C-o
         toggles the use of virtual buffers.
-        (ido-buffer-internal): Guard `ido-use-virtual-buffers' global
-        value.
+        (ido-buffer-internal): Guard `ido-use-virtual-buffers' global value.
         (ido-toggle-virtual-buffers): New function.
 
 2010-04-21  Juanma Barranquero  <lekktu@gmail.com>
@@ -4031,7 +4034,7 @@
 
         Enable recentf-mode if using virtual buffers.
         * ido.el (recentf-list): Declare for byte-compiler.
-        (ido-virtual-buffers): Move up to silence byte-compiler.  Add docstring.
+        (ido-virtual-buffers): Move up to silence byte-compiler. Add docstring.
         (ido-make-buffer-list): Simplify.
         (ido-add-virtual-buffers-to-list): Simplify.  Enable recentf-mode.
 
@@ -5542,8 +5545,8 @@
 2010-01-21  Alan Mackenzie  <acm@muc.de>
 
         Fix a situation where deletion of a cpp construct throws an error.
-        * progmodes/cc-engine.el (c-invalidate-state-cache): Before
-        invoking c-with-all-but-one-cpps-commented-out, check that the
+        * progmodes/cc-engine.el (c-invalidate-state-cache):
+        Before invoking c-with-all-but-one-cpps-commented-out, check that the
         special cpp construct is still in the buffer.
         (c-parse-state): Record the special cpp with markers, not numbers.
 
diff --git a/lisp/vc/add-log.el b/lisp/vc/add-log.el
index cf391b2f9ac..23f1e33f181 100644
--- a/lisp/vc/add-log.el
+++ b/lisp/vc/add-log.el
@@ -755,7 +755,17 @@ Optional arg BUFFER-FILE overrides `buffer-file-name'."
     (if add-log-file-name-function
         (funcall add-log-file-name-function buffer-file)
       (setq buffer-file
-            (file-relative-name buffer-file (file-name-directory log-file)))
+            (let* ((dir (file-name-directory log-file))
+                   (rel (file-relative-name buffer-file dir)))
+              ;; Sometimes with symlinks, the two buffers may have names that
+              ;; appear to belong to different directory trees.  So check the
+              ;; file-truenames, to see if we get a better result.
+              (if (not (string-match "\\`\\.\\./" rel))
+                  rel
+                (let ((new (file-relative-name (file-truename buffer-file)
+                                               (file-truename dir))))
+                  (if (< (length new) (length rel))
+                      new rel)))))
       ;; If we have a backup file, it's presumably because we're
       ;; comparing old and new versions (e.g. for deleted
       ;; functions) and we'll want to use the original name.