From 9c50bb5c01475bed7f19f42d7a2453c3f86dcaf8 Mon Sep 17 00:00:00 2001
From: ahocevar <andreas.hocevar@gmail.com>
Date: Fri, 16 Dec 2011 11:22:31 +0100
Subject: [PATCH 1/2] Don't set the new lonlat if the new zoom is not valid.

This avoids unwanted panning without zooming when using the mousewheel to zoom out on a wrapDateLine map (see #109).
---
 lib/OpenLayers/Map.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/lib/OpenLayers/Map.js b/lib/OpenLayers/Map.js
index adf2fc25d1..45a21a57e6 100644
--- a/lib/OpenLayers/Map.js
+++ b/lib/OpenLayers/Map.js
@@ -1749,7 +1749,12 @@ OpenLayers.Map = OpenLayers.Class({
             }
         }
         if (this.baseLayer.wrapDateLine) {
+            var requestedZoom = zoom;
             zoom = this.adjustZoom(zoom);
+            if (zoom !== requestedZoom) {
+                // zoom was adjusted, so keep old lonlat to avoid panning
+                lonlat = this.getCenter();
+            }
         }
         // dragging is false by default
         var dragging = options.dragging || this.dragging;

From 701e171081ccadfe5550c464cccb1955d983d1ca Mon Sep 17 00:00:00 2001
From: ahocevar <andreas.hocevar@gmail.com>
Date: Fri, 16 Dec 2011 11:48:08 +0100
Subject: [PATCH 2/2] Adding test to make sure we don't pan.

---
 tests/Map.html | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/tests/Map.html b/tests/Map.html
index 856434ac6d..faad0b30c7 100644
--- a/tests/Map.html
+++ b/tests/Map.html
@@ -380,11 +380,13 @@
  */
 
     function test_Map_isValidZoomLevel(t) {
-        t.plan(4);
+        t.plan(5);
         var map = new OpenLayers.Map("map");
         map.addLayer(new OpenLayers.Layer(null, {
-            isBaseLayer: true, numZoomLevels: 19
-        }))
+            isBaseLayer: true, wrapDateLine: true, numZoomLevels: 19
+        }));
+        map.zoomToMaxExtent();
+        
         var valid;
 
         valid = OpenLayers.Map.prototype.isValidZoomLevel.apply(map, [-1]);
@@ -398,6 +400,9 @@
 
         valid = OpenLayers.Map.prototype.isValidZoomLevel.apply(map, [19]);
         t.eq(valid, false, "19 is not a valid zoomLevel");
+        
+        map.moveTo([16, 48], 0);
+        t.eq(map.getCenter().toShortString(), "0, 0", "no panning when moveTo is called with invalid zoom");
 
         map.destroy();
     }
@@ -1966,7 +1971,7 @@
     }
 
     function test_adjustZoom(t) {
-        t.plan(3);
+        t.plan(4);
         var map = new OpenLayers.Map({
             div: 'map',
             layers: [
@@ -1981,6 +1986,9 @@
         
         t.eq(map.adjustZoom(9), 9, "valid zoom maintained");
         t.eq(map.adjustZoom(1), 2, "zoom adjusted to not exceed world width");
+
+        map.moveTo([16, 48], 0);
+        t.eq(map.getCenter().toShortString(), "0, 0", "no panning when moveTo is called with invalid zoom");
     }
 
   </script>