From: Russell Bryant <russell@russellbryant.com>
Date: Mon, 20 Jul 2009 16:36:15 +0000 (+0000)
Subject: Merged revisions 207360 via svnmerge from
X-Git-Tag: 11.0.0-beta1~4473
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=44301c95d29b1f8cf32690000541c0ee5edb0bef;p=thirdparty%2Fasterisk.git

Merged revisions 207360 via svnmerge from
https://origsvn.digium.com/svn/asterisk/branches/1.4

........
  r207360 | russell | 2009-07-20 11:26:24 -0500 (Mon, 20 Jul 2009) | 9 lines

  Only do the chan->fdno check in ast_read() in a developer build.

  I changed this check to only happen in a dev-mode build.  I also added a
  comment explaining what is going on.  I also made it so that detection of
  this situation does not affect ast_read() operation.

  (closes issue #14723)
  Reported by: seadweller
........


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@207361 65c4cc65-6c06-0410-ace0-fbb531ad65f3
---

diff --git a/main/channel.c b/main/channel.c
index da7d3ac62b..dce0747d57 100644
--- a/main/channel.c
+++ b/main/channel.c
@@ -3021,15 +3021,20 @@ static struct ast_frame *__ast_read(struct ast_channel *chan, int dropaudio)
 		goto done;
 	}
 
-	if (chan->fdno == -1) {
 #ifdef AST_DEVMODE
+	/* 
+	 * The ast_waitfor() code records which of the channel's file descriptors reported that
+	 * data is available.  In theory, ast_read() should only be called after ast_waitfor()
+	 * reports that a channel has data available for reading.  However, there still may be
+	 * some edge cases throughout the code where ast_read() is called improperly.  This can
+	 * potentially cause problems, so if this is a developer build, make a lot of noise if
+	 * this happens so that it can be addressed. 
+	 */
+	if (chan->fdno == -1) {
 		ast_log(LOG_ERROR, "ast_read() called with no recorded file descriptor.\n");
-#else
-		ast_debug(2, "ast_read() called with no recorded file descriptor.\n");
-#endif
-		f = &ast_null_frame;
-		goto done;
 	}
+#endif
+
 	prestate = chan->_state;
 
 	/* Read and ignore anything on the alertpipe, but read only