distgit: Avoid reupload

The script checks for the file at the new location.

As a result, it will report that the file is missing if it had only been
uploaded to the old location, which will prompt the client to reupload.

With this change, the script will check at the new location, and if it
doesn't find the file it will try checking for it at the old location as
well.

If the file is found at the old location, we hardlink it to the new
location, and report the file is available.

roles/distgit/files/dist-git-upload.cgi

@@ -65,6 +65,27 @@ def check_auth(username):
         pass
     return authenticated
 
+
+def hardlink(src, dest):
+    try:
+        os.makedirs(os.path.dirname(dest))
+
+    except OSError as e:
+        if e.errno != errno.EEXIST:
+            send_error(str(e))
+
+    try:
+        os.link(src, dest)
+
+    except OSError as e:
+        if e.errno != errno.EEXIST:
+            send_error(str(e))
+
+        # The file already existed at the dest path, hardlink over it
+        os.unlink(dest)
+        os.link(src, dest)
+
+
 def main():
     os.umask(002)
 
@@ -137,6 +158,9 @@ def main():
 
     # try to see if we already have this file...
     dest_file = os.path.join(hash_dir, filename)
+    old_dir = os.path.join(module_dir, filename, checksum)
+    old_path = os.path.join(old_dir, filename)
+
     if os.path.exists(dest_file):
         if action == 'check':
             print 'Available'
@@ -147,7 +171,13 @@ def main():
             print 'File: %s Size: %d' % (dest_file, dest_file_stat.st_size)
         sys.exit(0)
     elif action == 'check':
-        print 'Missing'
+        if os.path.exists(old_path):
+            # The file had been uploaded at the old path
+            hardlink(old_path, dest_file)
+            print 'Available'
+        else:
+            print 'Missing'
+
         sys.exit(0)
 
     # check that all directories are in place
@@ -191,26 +221,7 @@ def main():
 
     # Add the file to the old path, where fedpkg is currently looking for it
     if hash_type == "md5":
-        old_dir = os.path.join(module_dir, filename, checksum)
-        old_path = os.path.join(old_dir, filename)
-
-        try:
-            os.makedirs(old_dir)
-
-        except OSError as e:
-            if e.errno != errno.EEXIST:
-                send_error(str(e))
-
-        try:
-            os.link(dest_file, old_path)
-
-        except OSError as e:
-            if e.errno != errno.EEXIST:
-                send_error(str(e))
-
-            # The file already existed at the old path, hardlink over it
-            os.unlink(old_path)
-            os.link(dest_file, old_path)
+        hardlink(dest_file, old_path)
 
     # Emit a fedmsg message.  Load the config to talk to the fedmsg-relay.
     try: