map: fix coord picker on first click

lib/map.js

@@ -85,7 +85,8 @@ define(["map/clientlayer", "map/labelslayer",
         var button = L.DomUtil.create("button", "coord-picker")
         button.textContent = ""
 
-        L.DomEvent.disableClickPropagation(button)
+        // Click propagation isn't disabled as this causes problems with the
+        // location picking mode; instead propagation is stopped in onClick().
         L.DomEvent.addListener(button, "click", this.onClick, this)
 
         this.button = button
@@ -102,7 +103,8 @@ define(["map/clientlayer", "map/labelslayer",
         this.update()
       },
 
-      onClick: function () {
+      onClick: function (e) {
+        L.DomEvent.stopPropagation(e)
         this.f(!this.active)
       }