diff --git a/.travis.yml b/.travis.yml
index f3389f9245..b8387b04d6 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -8,8 +8,10 @@ node_js:
   - 8
 
 addons:
-  firefox: latest  # version 55.0 - 57.x have an issue with screenshots.
-  # firefox: 54.0.1
+  # version 55.0 - 57.x have an issue with screenshots.
+  # version 67.0 has an issue with touch events.
+  # firefox: latest
+  firefox: 66.0.5
   # We can change to a specific version of Chrome later.  Versions 68 - 70 have
   # an issue with webgl fallback rendering.
   chrome: stable
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 53b32dcba8..b200325416 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,16 @@
 # Change Log
 
+## Unreleased
+
+### Features
+- Fetch queues can have an initial size different from their regular size (#1000)
+
+### Improvements
+- More response zooming via mouse wheel (#993)
+
+### Bug Fixes
+- Better handling of tiles with overlap (#997)
+
 ## Version 0.19.4
 
 ### Improvements
diff --git a/src/map.js b/src/map.js
index 05174b496f..39fca1d5fb 100644
--- a/src/map.js
+++ b/src/map.js
@@ -355,7 +355,7 @@ var map = function (arg) {
       var oldCenter = m_this.center(undefined, undefined);
       m_gcs = arg;
       reset_minimum_zoom();
-      var newZoom = fix_zoom(m_zoom);
+      var newZoom = m_this._fix_zoom(m_zoom);
       if (newZoom !== m_zoom) {
         m_this.zoom(newZoom);
       }
@@ -417,7 +417,7 @@ var map = function (arg) {
 
     /* The ignoreDiscreteZoom flag is intended to allow non-integer zoom values
      * during animation. */
-    val = fix_zoom(val, ignoreDiscreteZoom);
+    val = m_this._fix_zoom(val, ignoreDiscreteZoom);
     if (val === m_zoom) {
       return m_this;
     }
@@ -683,7 +683,7 @@ var map = function (arg) {
     m_height = arg.height || m_height;
 
     reset_minimum_zoom();
-    var newZoom = fix_zoom(m_zoom);
+    var newZoom = m_this._fix_zoom(m_zoom);
     if (newZoom !== m_zoom) {
       m_this.zoom(newZoom);
     }
@@ -1144,7 +1144,7 @@ var map = function (arg) {
       },
       end: {
         center: opts.center,
-        zoom: fix_zoom(opts.zoom),
+        zoom: m_this._fix_zoom(opts.zoom),
         rotation: fix_rotation(opts.rotation, undefined, true)
       },
       ease: opts.ease,
@@ -1205,7 +1205,7 @@ var map = function (arg) {
       if (time >= m_transition.end.time || next) {
         if (!next) {
           if (m_transition.end.center) {
-            var needZoom = m_zoom !== fix_zoom(m_transition.end.zoom);
+            var needZoom = m_zoom !== m_this._fix_zoom(m_transition.end.zoom);
             m_this.center(m_transition.end.center, null, needZoom, needZoom);
           }
           m_this.zoom(m_transition.end.zoom, m_transition.zoomOrigin);
@@ -1236,7 +1236,7 @@ var map = function (arg) {
       if (m_transition.zCoord) {
         p[2] = z2zoom(p[2]);
       }
-      if (fix_zoom(p[2], true) === m_zoom) {
+      if (m_this._fix_zoom(p[2], true) === m_zoom) {
         m_this.center({
           x: p[0],
           y: p[1]
@@ -1408,7 +1408,7 @@ var map = function (arg) {
     }
 
     // calculate the zoom to fit the bounds
-    zoom = fix_zoom(calculate_zoom(bounds, rotation));
+    zoom = m_this._fix_zoom(calculate_zoom(bounds, rotation));
 
     // clamp bounds if necessary
     bounds = fix_bounds(bounds, rotation);
@@ -1453,7 +1453,7 @@ var map = function (arg) {
 
     gcs = (gcs === null ? m_gcs : (gcs === undefined ? m_ingcs : gcs));
     // preprocess the arguments
-    zoom = fix_zoom(zoom, ignoreDiscreteZoom);
+    zoom = m_this._fix_zoom(zoom, ignoreDiscreteZoom);
     units = m_this.unitsPerPixel(zoom);
     center = m_this.gcsToWorld(center, null);
 
@@ -1846,6 +1846,33 @@ var map = function (arg) {
     return m_animationQueue[0];
   };
 
+  /**
+   * Return the nearest valid zoom level to the requested zoom.
+   * @param {number} zoom A zoom level to adjust to current settings
+   * @param {boolean} ignoreDiscreteZoom If `true`, ignore the `discreteZoom`
+   *    option when determining the new view.
+   * @returns {number} The zoom level clamped to the allowed zoom range and
+   *    with other settings applied.
+   * @private
+   */
+  this._fix_zoom = function (zoom, ignoreDiscreteZoom) {
+    zoom = Math.round(zoom * 1e6) / 1e6;
+    zoom = Math.max(
+      Math.min(
+        m_validZoomRange.max,
+        zoom
+      ),
+      m_validZoomRange.min
+    );
+    if (m_discreteZoom && !ignoreDiscreteZoom) {
+      zoom = Math.round(zoom);
+      if (zoom < m_validZoomRange.min) {
+        zoom = Math.ceil(m_validZoomRange.min);
+      }
+    }
+    return zoom;
+  };
+
   /**
    * Draw a layer image to a canvas context.  The layer's opacity and transform
    * are applied.  This is used as part of making a screenshot.
@@ -2036,33 +2063,6 @@ var map = function (arg) {
     }
   }
 
-  /**
-   * Return the nearest valid zoom level to the requested zoom.
-   * @param {number} zoom A zoom level to adjust to current settings
-   * @param {boolean} ignoreDiscreteZoom If `true`, ignore the `discreteZoom`
-   *    option when determining the new view.
-   * @returns {number} The zoom level clamped to the allowed zoom range and
-   *    with other settings applied.
-   * @private
-   */
-  function fix_zoom(zoom, ignoreDiscreteZoom) {
-    zoom = Math.round(zoom * 1e6) / 1e6;
-    zoom = Math.max(
-      Math.min(
-        m_validZoomRange.max,
-        zoom
-      ),
-      m_validZoomRange.min
-    );
-    if (m_discreteZoom && !ignoreDiscreteZoom) {
-      zoom = Math.round(zoom);
-      if (zoom < m_validZoomRange.min) {
-        zoom = Math.ceil(m_validZoomRange.min);
-      }
-    }
-    return zoom;
-  }
-
   /**
    * Return a valid rotation angle.
    *
@@ -2312,7 +2312,7 @@ var map = function (arg) {
 
   // Fix the zoom level (minimum and initial)
   this.zoomRange(arg, true);
-  m_zoom = fix_zoom(m_zoom);
+  m_zoom = this._fix_zoom(m_zoom);
   m_rotation = fix_rotation(m_rotation);
   // Now update to the correct center and zoom level
   this.center($.extend({}, arg.center || m_center), undefined);
diff --git a/src/mapInteractor.js b/src/mapInteractor.js
index 457f92eb0e..42a1b5ba32 100644
--- a/src/mapInteractor.js
+++ b/src/mapInteractor.js
@@ -1603,31 +1603,36 @@ var mapInteractor = function (args) {
               zoom = startZoom + (targetZoom > startZoom ? 1 : -1);
             }
           }
-          map.transitionCancel('debounced_zoom.' + geo_action.zoom);
-          map.transition({
-            zoom: zoom,
-            zoomOrigin: origin,
-            duration: m_options.zoomAnimation.duration,
-            ease: m_options.zoomAnimation.ease,
-            done: function (status) {
-              status = status || {};
-              var zoomRE = new RegExp('\\.' + geo_action.zoom + '$');
-              if (!status.next && (!status.cancel ||
-                  ('' + status.source).search(zoomRE) < 0)) {
-                targetZoom = undefined;
+          zoom = Math.round(map._fix_zoom(zoom) * 1e6) / 1e6;
+          if (zoom !== map.zoom()) {
+            map.transitionCancel('debounced_zoom.' + geo_action.zoom);
+            map.transition({
+              zoom: zoom,
+              zoomOrigin: origin,
+              duration: m_options.zoomAnimation.duration,
+              ease: m_options.zoomAnimation.ease,
+              done: function (status) {
+                status = status || {};
+                var zoomRE = new RegExp('\\.' + geo_action.zoom + '$');
+                if (!status.next && (!status.cancel ||
+                    ('' + status.source).search(zoomRE) < 0)) {
+                  targetZoom = undefined;
+                }
+                /* If we were animating the zoom, if the zoom is continuous, just
+                 * stop where we are.  If using discrete zoom, we need to make
+                 * sure we end up discrete.  However, we don't want to do that if
+                 * the next action is further zooming. */
+                if (m_options.discreteZoom && status.cancel &&
+                    status.transition && status.transition.end &&
+                    ('' + status.source).search(zoomRE) < 0) {
+                  map.zoom(status.transition.end.zoom,
+                           status.transition.end.zoomOrigin);
+                }
               }
-              /* If we were animating the zoom, if the zoom is continuous, just
-               * stop where we are.  If using discrete zoom, we need to make
-               * sure we end up discrete.  However, we don't want to do that if
-               * the next action is further zooming. */
-              if (m_options.discreteZoom && status.cancel &&
-                  status.transition && status.transition.end &&
-                  ('' + status.source).search(zoomRE) < 0) {
-                map.zoom(status.transition.end.zoom,
-                         status.transition.end.zoomOrigin);
-              }
-            }
-          });
+            });
+          } else {
+            targetZoom = undefined;
+          }
         } else {
           zoom = deltaZ + map.zoom();
           if (m_options.discreteZoom) {