From: Aidan Van Dyk <aidan@ifax.com>
Date: Wed, 14 Mar 2007 18:31:19 +0000 (+0000)
Subject: Handle situation when sender is not using ECM after negotiating it.
X-Git-Tag: HYLAFAX-4_4_0BETA1~109
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=fa8d380e9f5ff28a5d0dfcfde358260a2beea50d;p=thirdparty%2FHylaFAX.git

Handle situation when sender is not using ECM after negotiating it.

From Lee:
|  commit de49a7b7b5dc5a2b704ef844fe90053d568dd0b8
|  Author: Lee Howard <faxguy@howardsilvan.com>
|  Date:   Thu Jun 29 16:27:15 2006 +0000
|
|    handle instances where the sender transmits MPS/EOP/EOM after a bunch of
|    garbage ECM data - indicating that the sender is not using ECM ... even
|    though we appear to have negotiated it
---

diff --git a/CHANGES b/CHANGES
index 1cb95d50..a1ef623d 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,6 +2,8 @@
 
 Changelog since HylaFAX 4.3.3
 
+* Handle instances where ECM is negotiated but the sender
+  transmits non-ECM data and signalling (12 Mar 2007)
 * Handle MPS/EOP/EOM/CRP when expecting DCS, i.e. after RTN
 * Log correctly when a receiver DIS indicates no V.8 bit but
   V.8 was already known to have succeeded (12 Mar 2007)
diff --git a/faxd/Class1Recv.c++ b/faxd/Class1Recv.c++
index ea8fe5cb..a489dffd 100644
--- a/faxd/Class1Recv.c++
+++ b/faxd/Class1Recv.c++
@@ -737,7 +737,22 @@ Class1Modem::recvPage(TIFF* tif, u_int& ppm, fxStr& emsg, const fxStr& id)
 		if (!getRecvEOLCount()) {
 		    // We have a null page, don't save it because it makes readers fail.
 		    pageGood = false;
-		    if (params.ec != EC_DISABLE) return (false);
+		    if (params.ec != EC_DISABLE) {
+			if (emsg == "") {
+			    /*
+			     * We negotiated ECM, got no valid ECM image data, and the 
+			     * ECM page reception routines did not set an error message.
+			     * The empty emsg is due to the ECM routines detecting a 
+			     * non-ECM-specific partial-page signal and wants it to
+			     * be handled here.  The sum total of all of this, and the 
+			     * fact that we got MPS/EOP/EOM tells us that the sender
+			     * is not using ECM.  In an effort to salvage the session we'll
+			     * disable ECM now and try to continue.
+			     */
+			    params.ec = EC_DISABLE;
+			} else
+			    return (false);
+		    }
 		}
 		if (!pageGood && conf.badPageHandling == FaxModem::BADPAGE_RTN)
 		    recvResetPage(tif);