Upstream-Status: Backport

--- a/subversion/mod_dav_svn/liveprops.c
+++ b/subversion/mod_dav_svn/liveprops.c
@@ -410,7 +410,8 @@ insert_prop(const dav_resource *resource
         svn_filesize_t len = 0;
 
         /* our property, but not defined on collection resources */
-        if (resource->collection || resource->baselined)
+        if (resource->type == DAV_RESOURCE_TYPE_ACTIVITY
+            || resource->collection || resource->baselined)
           return DAV_PROP_INSERT_NOTSUPP;
 
         serr = svn_fs_file_length(&len, resource->info->root.root,
@@ -434,7 +435,9 @@ insert_prop(const dav_resource *resource
         svn_string_t *pval;
         const char *mime_type = NULL;
 
-        if (resource->baselined && resource->type == DAV_RESOURCE_TYPE_VERSION)
+        if (resource->type == DAV_RESOURCE_TYPE_ACTIVITY
+            || (resource->baselined
+                && resource->type == DAV_RESOURCE_TYPE_VERSION))
           return DAV_PROP_INSERT_NOTSUPP;
 
         if (resource->type == DAV_RESOURCE_TYPE_PRIVATE
