Unable to use upload.py with a symlink and mercurial

I have a symlink in the codebase, and when I try to use upload.py it stops with 
the following error:

19:56:17:~/Development/workspace/ns-3-dev pecos$ ../upload.py --rev=5950 
--cc=ns-3-reviews@googlegroups.com --noisy
[... skip ...]
2013-03-10 19:54:55 INFO upload.py:759 Running ['hg', 'status', '-C', '--rev', 
'5950', 'doc/manual/source/figures'] 
Traceback (most recent call last):
  File "../upload.py", line 2394, in <module>
    main()
  File "../upload.py", line 2386, in main
    RealMain(sys.argv)
  File "../upload.py", line 2251, in RealMain
    files = vcs.GetBaseFiles(data)
  File "../upload.py", line 883, in GetBaseFiles
    files[filename] = self.GetBaseFile(filename)
  File "../upload.py", line 1566, in GetBaseFile
    new_content = open(relpath, "rb").read()
IOError: [Errno 21] Is a directory: 'doc/manual/source/figures'

The file it stops on is the following:

19:54:57:~/Development/workspace/ns-3-dev pecos$ ll doc/manual/source/figures
lrwxr-xr-x  1 pecos  staff  10 10 Mar 01:08 doc/manual/source/figures -> 
../figures

Trying manually the command gives the following result:
19:55:36:~/Development/workspace/ns-3-dev pecos$ hg status -C --rev 5950 
doc/manual/source/figures
A doc/manual/source/figures

The error happens with the latest upload.py, a MacOSX 10.8.2, mercurial 2.5.1

I don't know if this is a bug in mercurial or in upload.py. I guess the second 
since mercurial is perfectly working for its "normal" use.

Original issue reported on code.google.com by tommy...@gmail.com on 10 Mar 2013 at 7:12

v3ss0n / rietveld

Unable to use upload.py with a symlink and mercurial #426