Merge pull request openatv#3754 from WXbet/fix-channelscan-edgecase

[Scan] Fix services with same SID on different transponders overwriting each other

Author: jbleyel

lib/dvb/scan.cpp

@@ -828,10 +828,27 @@ void eDVBScan::channelDone()
 
 		m_ch_current->getHash(hash);
 
-		eDVBNamespace dvbnamespace = buildNamespace(
-			(**m_SDT->getSections().begin()).getOriginalNetworkId(),
-			(**m_SDT->getSections().begin()).getTransportStreamId(),
-			hash);
+		eOriginalNetworkID onid = (**m_SDT->getSections().begin()).getOriginalNetworkId();
+		eTransportStreamID tsid = (**m_SDT->getSections().begin()).getTransportStreamId();
+
+		eDVBNamespace dvbnamespace = buildNamespace(onid, tsid, hash);
+
+		/* Detect namespace collision: if a channel with the same stripped namespace+TSID+ONID
+		 * already exists in the database but points to a different physical transponder,
+		 * preserve the frequency in the namespace to keep services unique.
+		 * This prevents services with the same SID on different transponders (e.g. EBU feeds)
+		 * from overwriting each other during manual scan. */
+		eDVBChannelID chid_check(dvbnamespace, tsid, onid);
+		if (ePtr<iDVBFrontendParameters> existing_ch;
+			!eDVBDB::getInstance()->getChannelFrontendData(chid_check, existing_ch))
+		{
+			int diff = 0;
+			if (!m_ch_current->calculateDifference(&*existing_ch, diff, false) && diff > 0)
+			{
+				dvbnamespace = eDVBNamespace(hash);
+				SCAN_eDebug("[eDVBScan] namespace collision detected: different transponder uses same TSID/ONID, preserving frequency in namespace");
+			}
+		}
 
 		SCAN_eDebug("[eDVBScan] SDT: ");
 		std::vector<ServiceDescriptionSection*>::const_iterator i;
@@ -847,11 +864,25 @@ void eDVBScan::channelDone()
 		m_ch_current->getHash(hash);
 
 		int onid = 0; /* TODO: ATSC ONID? */
+		eTransportStreamID tsid = (**m_VCT->getSections().begin()).getTransportStreamId();
 		eDVBNamespace dvbnamespace = buildNamespace(
 			eOriginalNetworkID(onid),
-			(**m_VCT->getSections().begin()).getTransportStreamId(),
+			tsid,
 			hash);
 
+		/* Detect namespace collision (same as SDT block above) */
+		eDVBChannelID chid_check(dvbnamespace, tsid, eOriginalNetworkID(onid));
+		if (ePtr<iDVBFrontendParameters> existing_ch;
+			!eDVBDB::getInstance()->getChannelFrontendData(chid_check, existing_ch))
+		{
+			int diff = 0;
+			if (!m_ch_current->calculateDifference(&*existing_ch, diff, false) && diff > 0)
+			{
+				dvbnamespace = eDVBNamespace(hash);
+				SCAN_eDebug("[eDVBScan] namespace collision detected: different transponder uses same TSID/ONID, preserving frequency in namespace");
+			}
+		}
+
 		SCAN_eDebug("[eDVBScan] VCT: ");
 		std::vector<VirtualChannelTableSection*>::const_iterator i;
 		for (i = m_VCT->getSections().begin(); i != m_VCT->getSections().end(); ++i)