Created attachment 295242 [details] [review]
dav: Add support for server-side copying

Use webdav's COPY method to implement support for server-side copying.
This improves performance considerably, especially over slow
connections.

Created attachment 295243 [details] [review]
dav: Fix up error handling when moving

Don't leak the source and target URI when doing a server-side move.
Also, don't continue after giving an G_IO_ERROR_EXISTS.

Created attachment 295244 [details] [review]
dav: Trim some duplicated text

I tested the patch against Apache, IIS and sabredav.

I also attached a couple of extra patches which fix up some things I noticed.

Review of attachment 295243 [details] [review]:

Looks good!

Review of attachment 295242 [details] [review]:

Looks good, thanks!

::: daemon/gvfsbackenddav.c
@@ +2883,3 @@
+  source_uri = g_vfs_backend_dav_uri_for_path (backend, source, FALSE);
+  res = stat_location (backend, source_uri, &source_ft, NULL, &error);
+  if (!res)

Maybe would be good to get target_uri before this statement and use goto error here... (just idea)

@@ +2946,3 @@
+
+  if (SOUP_STATUS_IS_SUCCESSFUL (status))
+    {

The curly brackets here are redundant...

Pushed to master as be1191f1b2f3972441b2e8947d9a2ac71160a375 (with the suggested fixes). Thanks for the reviews!