overview: Protect ::drag-end handlers

These end up emitting item-drag-end/window-drag-end pretty much
without checks. Given the MetaDnd object may end up emitting
::drag-leave as a result of the plugin ending its grab, this
would result on spurious emission of those events and subsequent
warnings.

For extra paranoia, the _inDrag variable has been split into
_inItemDrag/_inWindowDrag so we can't cross the streams.

https://bugzilla.gnome.org/show_bug.cgi?id=784545

js/ui/overview.js

@@ -414,7 +414,7 @@ const Overview = new Lang.Class({
 
     beginItemDrag: function(source) {
         this.emit('item-drag-begin');
-        this._inDrag = true;
+        this._inItemDrag = true;
     },
 
     cancelledItemDrag: function(source) {
@@ -422,13 +422,15 @@ const Overview = new Lang.Class({
     },
 
     endItemDrag: function(source) {
+        if (!this._inItemDrag)
+            return;
         this.emit('item-drag-end');
-        this._inDrag = false;
+        this._inItemDrag = false;
     },
 
     beginWindowDrag: function(window) {
         this.emit('window-drag-begin', window);
-        this._inDrag = true;
+        this._inWindowDrag = true;
     },
 
     cancelledWindowDrag: function(window) {
@@ -436,8 +438,10 @@ const Overview = new Lang.Class({
     },
 
     endWindowDrag: function(window) {
+        if (!this._inWindowDrag)
+            return;
         this.emit('window-drag-end', window);
-        this._inDrag = false;
+        this._inWindowDrag = false;
     },
 
     focusSearch: function() {
@@ -481,7 +485,7 @@ const Overview = new Lang.Class({
     shouldToggleByCornerOrButton: function() {
         if (this.animationInProgress)
             return false;
-        if (this._inDrag)
+        if (this._inItemDrag || this._inWindowDrag)
             return false;
         if (this._activationTime == 0 || Date.now() / 1000 - this._activationTime > OVERVIEW_ACTIVATION_TIMEOUT)
             return true;

js/ui/padOsd.js

@@ -513,7 +513,7 @@ const PadDiagram = new Lang.Class({
     },
 
     getRingLabelCoords: function (number, dir) {
-        let numStr = number > 0 ? number.toString() : '';
+        let numStr = number > 0 ? (number + 1).toString() : '';
         let dirStr = dir == CW ? 'CW' : 'CCW';
         let labelName = 'LabelRing' + numStr + dirStr;
         let leaderName = 'LeaderRing' + numStr + dirStr;