ported bug fix about directory handling with download from 1.4 branch

git-svn-id: http://svn.zope.org/repos/main/zc.buildout/trunk@118894 62d5b8a3-27da-0310-9561-8e5933582275

CHANGES.txt

@@ -12,6 +12,11 @@ Change History
   due to missing support for the ``-E`` option, which only got added
   afterwards.
 
+Bugs fixed:
+
+- In the download module, fixed the handling of directories that are pointed
+  to by file-system paths and ``file:`` URLs.
+
 1.5.2 (2010-10-11)
 ==================
 

src/zc/buildout/download.py

@@ -118,7 +118,7 @@ class Download(object):
         cached_path = os.path.join(cache_dir, cache_key)
 
         self.logger.debug('Searching cache at %s' % cache_dir)
-        if os.path.isfile(cached_path):
+        if os.path.exists(cached_path):
             is_temp = False
             if self.fallback:
                 try:
@@ -247,6 +247,9 @@ def locate_at(source, dest):
     if dest is None or realpath(dest) == realpath(source):
         return source
 
+    if os.path.isdir(source):
+        shutil.copytree(source, dest)
+    else:
         try:
             os.link(source, dest)
         except (AttributeError, OSError):

src/zc/buildout/download.txt

@@ -537,6 +537,25 @@ conversions:
 >>> path, is_temp = Download()(server_url+'foo.txt', md5(text).hexdigest())
 >>> remove(path)
 
+When "downloading" a directory given by file-system path or ``file:`` URL and
+using a download cache at the same time, the cached directory wasn't handled
+correctly. Consequently, the cache was defeated and an attempt to cache the
+directory a second time broke. This is how it should work:
+
+>>> download = Download(cache=cache)
+>>> dirpath = join(server_data, 'some_directory')
+>>> mkdir(dirpath)
+>>> dest, _ = download(dirpath)
+
+If we now modify the source tree, the second download will produce the
+original one from the cache:
+
+>>> mkdir(join(dirpath, 'foo'))
+>>> ls(dirpath)
+d foo
+>>> dest, _ = download(dirpath)
+>>> ls(dest)
+
 
 Clean up
 --------