🐛 Fix duplicated lines at the end of the minimap

This problem occurs when the only changes are screen lines changes due
to soft wrapping (by splitting panes, resizing the window, or just at
intialization). In that case, we don’t compute an extra intact range
that would copy a part of the offscreen buffer at the wrong place.

Fixes #292

lib/mixins/canvas-drawer.coffee

@@ -444,11 +444,14 @@ class CanvasDrawer extends Mixin
               end: change.start - 1
               domStart: range.domStart)
           if change.end < range.end
-            newIntactRanges.push(
-              start: change.end + change.screenDelta + 1
-              end: range.end + change.screenDelta
-              domStart: range.domStart + change.end + 1 - range.start
-            )
+            # If the bufferDelta is 0 then it's a change in the screen lines
+            # due to soft wrapping, we don't need to touch to the intact ranges
+            unless change.bufferDelta is 0
+              newIntactRanges.push(
+                start: change.end + change.screenDelta + 1
+                end: range.end + change.screenDelta
+                domStart: range.domStart + change.end + 1 - range.start
+              )
 
         intactRange = newIntactRanges[newIntactRanges.length - 1]