Added a cautionary note to the docstring for serve_fileobj(), regarding the seek() performed on the file object when the request has a 'Range' header, and how this may result in incorrect behavior.

1 files changed, 7 insertions, 0 deletions

diff --git a/cherrypy/lib/static.py b/cherrypy/lib/static.py
index 47d41748..697fa8e8 100644
--- a/cherrypy/lib/static.py
+++ b/cherrypy/lib/static.py
@@ -85,6 +85,13 @@ def serve_fileobj(fileobj, content_type=None, disposition=None, name=None):
     to "<disposition>; filename=<name>". If name is None, 'filename' will
     not be set. If disposition is None, no Content-Disposition header will
     be written.
+
+    CAUTION: If the request contains a 'Range' header, one or more seek()s will
+    be performed on the file object.  This may cause undesired behavior if
+    the file object is not seekable.  It could also produce undesired results
+    if the caller set the read position of the file object prior to calling
+    serve_fileobj(), expecting that the data would be served starting from that
+    position.
     """
     
     response = cherrypy.response