[Nexus] Predictive tuning: Fix crash when starting playback

pvr.hts/addon.xml.in

@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <addon
   id="pvr.hts"
-  version="20.7.1"
+  version="20.7.2"
   name="Tvheadend HTSP Client"
   provider-name="Adam Sutton, Sam Stenvall, Lars Op den Kamp, Kai Sommerfeld">
   <requires>@ADDON_DEPENDS@</requires>

pvr.hts/changelog.txt

@@ -1,3 +1,7 @@
+v20.7.2
+- Predictive tuning: Fix crash when starting playback of a channel which has no unique channel number
+  (tvh does not prevent duplicate channel numbers).
+
 v20.7.1
 - Translations updates from Weblate
 	- af_za, ca_es, cs_cz, da_dk, en_nz, es_es, es_mx, fi_fi, fr_ca, fr_fr, hr_hr, hu_hu, is_is, it_it, ko_kr, mk_mk, nb_no, nl_nl, pt_br, pt_pt, ro_ro, ru_ru, sk_sk, sl_si, sr_rs, sr_rs@latin, sv_se, tr_tr, zh_cn, zh_tw

src/tvheadend/ChannelTuningPredictor.h

@@ -68,7 +68,11 @@ struct SortChannelPair
 {
   bool operator()(const ChannelPair& left, const ChannelPair& right) const
   {
-    return left.second < right.second;
+    if (left.second < right.second)
+      return true;
+
+    // if channel numbers are equal, consider channel id (which is unique)
+    return left.first < right.first;
   }
 };
 } // namespace predictivetune