Marcel Wiesweg wrote:
Hi,
I just ran into a problem with cChannel's copy constructor. The problem is that this is actually not a copy constructor, because it sets the values to 0 instead of copying, and - most important - it behaves different from operator=.
It seems these two are not used in VDR except for one place (where I found this), cSectionHandler::SetChannel. The value stored by cSectionHandle has nid,tid,sid set to 0. In the line shp->channel = Channel ? *Channel : cChannel(); there seems only the operator= involved, but actually the copy constructor is invoked before the *Channel is given to opertator=. Attached is a short test program which illustrates the problem.
Solution is to make the copy constructor do copying.
The "copy constructor" is actually used intentionally in cChannels::NewChannel(), where its sole purpose is to copy the actual transponder data. But you're of course right, a copy constructor should behave like a real copy constructor, and not serve a very special purpose.
I have therefore introduced cChannel::CopyTransponderData() for that purpose, and changed the copy ctor so that it calls operator=. See the attached patch and let me know if this works for you.
Klaus
--- channels.h 2005/05/28 13:57:08 1.32 +++ channels.h 2005/08/06 11:23:32 @@ -181,6 +181,7 @@ bool IsTerr(void) const { return cSource::IsTerr(source); } tChannelID GetChannelID(void) const { return tChannelID(source, nid, (nid || tid) ? tid : Transponder(), sid, rid); } int Modification(int Mask = CHANNELMOD_ALL); + void CopyTransponderData(const cChannel *Channel); bool SetSatTransponderData(int Source, int Frequency, char Polarization, int Srate, int CoderateH); bool SetCableTransponderData(int Source, int Frequency, int Modulation, int Srate, int CoderateH); bool SetTerrTransponderData(int Source, int Frequency, int Bandwidth, int Modulation, int Hierarchy, int CodeRateH, int CodeRateL, int Guard, int Transmission); --- channels.c 2005/05/29 10:32:38 1.42 +++ channels.c 2005/08/06 12:06:37 @@ -179,27 +179,13 @@
cChannel::cChannel(const cChannel &Channel) { - name = strdup(""); - shortName = strdup(""); - provider = strdup(""); - portalName = strdup(""); - *this = Channel; - vpid = 0; - ppid = 0; - apids[0] = 0; - dpids[0] = 0; - spids[0] = 0; - tpid = 0; - caids[0] = 0; - nid = 0; - tid = 0; - sid = 0; - rid = 0; - number = 0; - groupSep = false; - modification = CHANNELMOD_NONE; + name = NULL; + shortName = NULL; + provider = NULL; + portalName = NULL; linkChannels = NULL; refChannel = NULL; + *this = Channel; }
cChannel::~cChannel() @@ -265,6 +251,24 @@ return Result; }
+void cChannel::CopyTransponderData(const cChannel *Channel) +{ + if (Channel) { + frequency = Channel->frequency; + source = Channel->source; + srate = Channel->srate; + polarization = Channel->polarization; + inversion = Channel->inversion; + bandwidth = Channel->bandwidth; + coderateH = Channel->coderateH; + coderateL = Channel->coderateL; + modulation = Channel->modulation; + transmission = Channel->transmission; + guard = Channel->guard; + hierarchy = Channel->hierarchy; + } +} + bool cChannel::SetSatTransponderData(int Source, int Frequency, char Polarization, int Srate, int CoderateH) { // Workarounds for broadcaster stupidity: @@ -977,7 +981,8 @@ { if (Transponder) { dsyslog("creating new channel '%s,%s;%s' on %s transponder %d with id %d-%d-%d-%d", Name, ShortName, Provider, *cSource::ToString(Transponder->Source()), Transponder->Transponder(), Nid, Tid, Sid, Rid); - cChannel *NewChannel = new cChannel(*Transponder); + cChannel *NewChannel = new cChannel; + NewChannel->CopyTransponderData(Transponder); NewChannel->SetId(Nid, Tid, Sid, Rid); NewChannel->SetName(Name, ShortName, Provider); Add(NewChannel);