svn commit: r314701 - head/lib/libfetch

[Dag-Erling Smørgrav]

Author: des
Date: Sun Mar  5 12:06:45 2017
New Revision: 314701
URL: https://svnweb.freebsd.org/changeset/base/314701

Log:
  Fix partial requests (used by fetch -r) when the requested file is
  already complete.
  
  Since 416 is an error code, any Content-Range header in the response
  would refer to the error message, not the requested document, so
  relying on the value of size when we know we got a 416 is wrong.
  Instead, just verify that offset == 0 and assume that we've reached
  the end of the document (if offset > 0, we did not request a range,
  and the server is screwing with us).  Note that we cannot distinguish
  between reaching the end and going past it, but that is a flaw in the
  protocol, not in the code, so we just have to assume that the caller
  knows what it's doing.  A smart caller would request an offset
  slightly before what it believes is the end and compare the result to
  what is already in the file.
  
  PR:		212065
  Reported by:	mandree
  MFC after:	3 weeks

Modified:
  head/lib/libfetch/http.c

Modified: head/lib/libfetch/http.c
==============================================================================
--- head/lib/libfetch/http.c	Sun Mar  5 07:46:48 2017	(r314700)
+++ head/lib/libfetch/http.c	Sun Mar  5 12:06:45 2017	(r314701)
@@ -1925,7 +1925,7 @@ http_request_body(struct url *URL, const
 
 		/* requested range not satisfiable */
 		if (conn->err == HTTP_BAD_RANGE) {
-			if (url->offset == size && url->length == 0) {
+			if (url->offset > 0 && url->length == 0) {
 				/* asked for 0 bytes; fake it */
 				offset = url->offset;
 				clength = -1;