Symbolic link for trac.ini overwritten when saving Configuration object

[Ryan J Ollos]

I tried storing trac.ini in a version-controlled directory outside of the Environment, using a symbolic link in the Environment conf directory. The symbolic link is not followed when saving the Configuration object.

Using os.path.realpath seems to be the proper solution:

user@ubuntu:~/Workspace$ touch file
user@ubuntu:~/Workspace$ ln -s file link
user@ubuntu:~/Workspace$ ls -al file link
-rw-rw-r-- 1 user user 0 Mar 25 21:17 file
lrwxrwxrwx 1 user user 4 Mar 25 21:17 link -> file

Python 2.7.6 (default, Mar 22 2014, 22:59:56) 
[GCC 4.8.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import os
>>> os.path.realpath('/home/user/Workspace/link')
'/home/user/Workspace/file'

The following patch appears to work.

trac/config.py

@@ -129 +129 @@
     when the file has changed.
     """
     def __init__(self, filename, params={}):
-        self.filename = filename
+        self.filename = os.path.realpath(filename)  # follow any symlinks
         self.parser = UnicodeParser()
         self._parsed_sections = {}
         self.parents = []

Inherited files and files defined in PathOptions are resolved relative to the location of trac.ini. Before the patch this is always the Environment conf directory. I think the behaviour is better after the patch.

[Jun Omae]

Configuration.filename instance is used with os.path.dirname() in Seciotn.getpath() at tags/trac-1.0.5/trac/config.py@:481#L471​. Applying the patch would change behavior of PathOption, e.g. when $ENV/conf is a symbolic link.

I consider the root cause is that AtomicFile.commit() removes a symbolic file. We should modify AtomicFile class.

trac/util/__init__.py

@@ -170 +170 @@
     the temporary file is removed.
     """
     def __init__(self, path, mode='w', bufsize=-1):
+        path = os.path.realpath(path)
         self._file = None
         self._path = path
         (dir, name) = os.path.split(path)

[Ryan J Ollos]

Replying to rjollos:

Inherited files and files defined in PathOptions are resolved relative to the location of trac.ini. Before the patch this is always the Environment conf directory. I think the behaviour is better after the patch.

I've reconsidered based on comment:1. It will probably be better to store all files relative to the conf directory, rather than relative to trac.ini. We can just symlink all files in conf, if desired.

Proposed changes in log:rjollos.git:t12000. Tested on Ubuntu 14.04 and Windows 7.

[Ryan J Ollos]

Committed to 1.0-stable in [13934], merged to trunk in [13935].