Tested kde version was 4.8-rc1

I was able to reproduce the bug

Same thing happened to me (using KDE 4.7.3)

I have the same problem. In KDE 3.5 I was able to put 2 panels on the same edge. I designed a very cool desktop in kde 3 but now I'm not able to rebuild it in kde 4 because I cannot put 2 panels on the same edge without overlapping the other one.
Screenshot of how I would like to look my desktop like:
http://www.mediafire.com/i/?2mu9gat5329fby5

I have a similar issue where I have two maximized panels on abutting edges that overlap in the corner requiring me to manually adjust the size of one of the panels to not overlap.

Created attachment 72401 [details]
prevent overlap panels on same edge using docking

Comment on attachment 72401 [details]
prevent overlap panels on same edge using docking

--- plasma/desktop/shell/panelview.cpp.orig    2012-06-18 21:29:17.425013657 +0200
+++ plasma/desktop/shell/panelview.cpp    2012-06-21 20:38:32.326059299 +0200
@@ -1019,6 +1019,103 @@
         int topOffset = wholeScreen.top() - thisScreen.top();
         kDebug() << "screen l/r/b/t offsets are:" << leftOffset << rightOffset << bottomOffset << topOffset << location();
 
+    
+        int my_y = 0;
+        int my_x = 0;
+        int my_height = 0;
+        int my_width = 0;
+        int o_y = 0;
+        int o_x = 0;
+        int o_height = 0;
+        int o_width = 0;
+        QRectF myrect;
+        QRectF orect;
+        QRect m;
+        QRect o;
+        QString a;
+        QString b;
+
+        int cntTopP=0;
+        int cntBottomP=0;
+        int cntRightP=0;
+        int cntLeftP=0;
+        
+        foreach (Plasma::Containment *c, PlasmaApp::self()->corona()->containments()) 
+        {
+            if (c->containmentType() == Plasma::Containment::PanelContainment) 
+            {
+                if (c->location()==Plasma::TopEdge)
+                    cntTopP++;
+                if (c->location()==Plasma::BottomEdge)
+                    cntBottomP++;
+                if (c->location()==Plasma::RightEdge)
+                    cntRightP++;
+                if (c->location()==Plasma::LeftEdge)
+                    cntLeftP++;
+                
+                kDebug() << QString("countPanel Top Bottom Right Left: %1 %2 %3 %4 ").arg(cntTopP).arg(cntBottomP).arg(cntRightP).arg(cntLeftP);
+                
+                if (c == containment()) 
+                {
+                    if (c->view()  != NULL) {
+                        myrect=c->view()->geometry();
+                        
+                        my_y = c->view()->y();
+                        my_x = c->view()->x();
+                        my_width = c->geometry().width();
+                        my_height = c->geometry().height();
+                        m=myrect.toRect();
+                    }
+                    //a += " i'm self !!!";
+                }
+                else // check for same edge...
+                {
+                    //a += " Found other panel !!!";
+                    if (c->view()  != NULL) {    
+                        orect = c->view()->geometry();
+                        o_y = c->view()->y();
+                        o_x = c->view()->x();
+                        o_width = c->geometry().width();
+                        o_height = c->geometry().height();
+                        o=orect.toRect();
+                    }
+                    
+                    if (c->location() == location()) 
+                    {
+                        //a+= " other panel is on same edge!!!";
+                        //a+= QString().setNum(location());
+                        if  ( myrect.intersects(orect) ) 
+                        switch (location())
+                        {
+                        case Plasma::TopEdge:
+                            move(x(), y()+(cntTopP-1)*o_height);
+                            break;
+                        case Plasma::BottomEdge:
+                            move(x(), y() - (cntBottomP-1)*o_height);
+                            break;
+                        case Plasma::RightEdge:
+                            move(x() - (cntRightP-1)*o_width, y());
+                            break;
+                        case Plasma::LeftEdge:
+                            move(x() + (cntLeftP-1)*o_width, y());
+                            break;
+                        default:
+                            //kDebug() << "where are we?";
+                            break;
+                        }
+                    }
+                }
+            }
+            //else
+            //    a += "(other containment)";
+            
+            
+            /*
+            b.sprintf("my: %d,%d %dx%d, other: %d,%d %dx%d ", m.x(), m.y(), m.width(), m.height(), o.x(),  o.y(),  o.width(), o.height());
+            a += b;
+            kDebug() << "c: type: " << c->containmentType() << " " << a;*/
+       }
+       
         switch (location())
         {
             case Plasma::TopEdge:

Oh!
Many thanks! I will try it out!

(In reply to comment #6)
> Created attachment 72401 [details]
> prevent overlap panels on same edge using docking

Thank you for the patch. Could you please submit this to http://reviewboard.kde.org?

Still open in 4.10rc3

Hello!

This bug report was filed for KDE Plasma 4, which reached end-of-support status in August 2015. KDE Plasma 5's desktop shell has been almost completely rewritten for better performance and usability, so it is likely that this bug is already resolved in Plasma 5.

Accordingly, we hope you understand why we must close this bug report. If the issue described  here is still present in KDE Plasma 5.12 or later, please feel free to open a new ticket in the "plasmashell" product after reading https://community.kde.org/Get_Involved/Bug_Reporting

If you would like to get involved in KDE's bug triaging effort so that future mass bug closes like this are less likely, please read https://community.kde.org/Get_Involved#Bug_Triaging

Thanks for your understanding!

Nate Graham

Still valid with plasmashell.

*** This bug has been marked as a duplicate of bug 336374 ***