fix #635,never add primary dock over an explicit

--the addDock code now checks if at the primary screen
in the specific edge there is already assigned an explicit
dock. In that case it doesnt add that primary dock

app/dockcorona.cpp

@@ -866,6 +866,12 @@ void DockCorona::addDock(Plasma::Containment *containment, int expDockScreen)
             qDebug() << "adding dock rejected, screen not available : " << connector;
             return;
         }
+    } else if (onPrimary) {
+        if (explicitDockOccupyEdge(primaryScreenId(), containment->location())) {
+            //we must check that an onPrimary dock should never catch up the same edge on
+            //the same screen with an explicit dock
+            return;
+        }
     }
 
     qDebug() << "Adding dock for container...";
@@ -911,6 +917,22 @@ void DockCorona::addDock(Plasma::Containment *containment, int expDockScreen)
     emit docksCountChanged();
 }
 
+bool DockCorona::explicitDockOccupyEdge(int screen, Plasma::Types::Location location) const
+{
+    foreach (auto containment, containments()) {
+        bool onPrimary = containment->config().readEntry("onPrimary", true);
+        int id = containment->lastScreen();
+        Plasma::Types::Location contLocation = containment->location();
+
+        if (!onPrimary && id == screen && contLocation == location) {
+            return true;
+        }
+
+    }
+
+    return false;
+}
+
 void DockCorona::recreateDock(Plasma::Containment *containment)
 {
     //! give the time to config window to close itself first and then recreate the dock

app/dockcorona.h

@@ -125,6 +125,7 @@ private:
 
     bool appletExists(uint containmentId, uint appletId) const;
     bool containmentExists(uint id) const;
+    bool explicitDockOccupyEdge(int screen, Plasma::Types::Location location)const;
     bool heuresticForLoadingDockWithTasks();
     int noOfDocks();
     int primaryScreenId() const;