Merged revisions 290575 via svnmerge from

https://origsvn.digium.com/svn/asterisk/branches/1.6.2

........
  r290575 | tilghman | 2010-10-06 08:48:27 -0500 (Wed, 06 Oct 2010) | 8 lines
  
  Allow streaming audio from a pipe.
  
  (closes issue #18001)
   Reported by: jamicque
   Patches: 
         20100926__issue18001.diff.txt uploaded by tilghman (license 14)
   Tested by: jamicque
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@290576 65c4cc65-6c06-0410-ace0-fbb531ad65f3

main/file.c

@@ -959,10 +959,12 @@ int ast_streamfile(struct ast_channel *chan, const char *filename, const char *p
 	 * done this way because there is no where for ast_openstream_full to
 	 * return the file had no data. */
 	seekattempt = fseek(fs->f, -1, SEEK_END);
-	if (!seekattempt)
-		ast_seekstream(fs, 0, SEEK_SET);
-	else
+	if (seekattempt && errno == EINVAL) {
+		/* Zero-length file, as opposed to a pipe */
 		return 0;
+	} else {
+		ast_seekstream(fs, 0, SEEK_SET);
+	}
 
 	vfs = ast_openvstream(chan, filename, preflang);
 	if (vfs) {