Fix log scale

src/scale/Interval.js

@@ -36,6 +36,14 @@ define(function (require) {
                 thisExtent[1] += expandSize;
             }
         },
+
+        unionExtent: function (other) {
+            var extent = this._extent;
+            other[0] < extent[0] && (extent[0] = other[0]);
+            other[1] > extent[1] && (extent[1] = other[1]);
+
+            IntervalScale.prototype.setExtent.call(this, extent[0], extent[1]);
+        },
         /**
          * Get interval
          */

src/scale/Scale.js

@@ -62,8 +62,8 @@ define(function (require) {
         var extent = this._extent;
         other[0] < extent[0] && (extent[0] = other[0]);
         other[1] > extent[1] && (extent[1] = other[1]);
-        // Set again
-        this.setExtent(extent[0], extent[1]);
+        // not setExtent because in log axis it may transformed to power
+        // this.setExtent(extent[0], extent[1]);
     };
 
     /**