Configure Input Groups in mythtv-setup

Capture cards can be configured so that only one capture card of a
group of capture cards can be used at any one time. This is done
by defining an Input Group and then assigning that group to all
capture cards that are to be part of the group.
Configuring this with mythtv-setup has always been possible but there
was a bug that allowed only one card to be configured as member of an
input group. This bug is now fixed.

Based on commit 973edd2 in master.

Refs #698

mythtv/libs/libmythtv/cardutil.cpp

@@ -2016,10 +2016,18 @@ bool CardUtil::LinkInputGroup(uint inputid, uint inputgroupid)
         return false;
     }
 
-    if (!query.next())
-        return false;
+    QString name;
+    while (query.next()) {
+        name = query.value(2).toString();
+        uint cardid = query.value(0).toUInt();
+        // Already linked
+        if (cardid == inputid)
+            return true;
+    }
 
-    const QString name = query.value(2).toString();
+    // Invalid group id
+    if (name.isEmpty())
+        return false;
 
     query.prepare(
         "INSERT INTO inputgroup "
@@ -2036,6 +2044,9 @@ bool CardUtil::LinkInputGroup(uint inputid, uint inputgroupid)
         return false;
     }
 
+    // Now that there is a proper linkage, unlink temporary cardid 0
+    UnlinkInputGroup(0, inputgroupid);
+
     return true;
 }
 

mythtv/libs/libmythtv/videosource.cpp

@@ -2913,14 +2913,11 @@ class InputGroup : public TransMythUIComboBoxSetting
         uint inputid     = m_cardInput.getInputID();
         uint new_groupid = getValue().toUInt();
 
-        if (m_groupId)
+        if (m_groupId && (m_groupId != new_groupid))
             CardUtil::UnlinkInputGroup(inputid, m_groupId);
 
         if (new_groupid)
-        {
-            if (CardUtil::UnlinkInputGroup(inputid, new_groupid))
-                CardUtil::LinkInputGroup(inputid, new_groupid);
-        }
+            CardUtil::LinkInputGroup(inputid, new_groupid);
     }
 
     virtual void Save(const QString& /*destination*/) { Save(); }
@@ -3525,9 +3522,6 @@ void CardInput::Save(void)
     {
         CardUtil::CloneCard(cardid, 0);
     }
-
-    // Delete any unused input groups
-    CardUtil::UnlinkInputGroup(0,0);
 }
 
 int CardInputDBStorage::getInputID(void) const