demuxer - Seek - set m_seekTime variable to zero before Wait()

It's really a fatal error. If the predicate is not set to zero,
then _PredicateCallbackDefault() function (see platform/mutex.h)
gives true return value. It means that Wait() returns ASAP.

This also means that m_seekTime must not be set to a zero value
in the ParseSubscriptionSkip().

src/HTSPDemuxer.cpp

@@ -165,6 +165,7 @@ bool CHTSPDemuxer::Seek
   m_seeking = true;
 
   /* Wait for time */
+  m_seekTime = 0;
   if (!m_seekCond.Wait(m_conn.Mutex(), m_seekTime, Settings::GetInstance().GetResponseTimeout()))
   {
     Logger::Log(LogLevel::LEVEL_ERROR, "failed to get subscriptionSeek response");
@@ -178,7 +179,7 @@ bool CHTSPDemuxer::Seek
     return false;
 
   /* Store */
-  *startpts = TVH_TO_DVD_TIME(m_seekTime);
+  *startpts = TVH_TO_DVD_TIME(m_seekTime - 1);
   Logger::Log(LogLevel::LEVEL_TRACE, "demux seek startpts = %lf", *startpts);
 
   return true;
@@ -511,7 +512,7 @@ void CHTSPDemuxer::ParseSubscriptionSkip ( htsmsg_t *m )
   if (htsmsg_get_s64(m, "time", &s64)) {
     m_seekTime = INVALID_SEEKTIME;
   } else {
-    m_seekTime = s64;
+    m_seekTime = s64 < 0 ? 1 : s64 + 1; /* it must not be zero! */
   }
   Flush(); /* flush old packets (with wrong pts) */
   m_seekCond.Broadcast();