Ensure selections span the entire screen, even when lines are short

Also, pass scrollHeight and scrollWidth as props to child components
instead of calling the method to compute them in multiple components.

src/editor-component.coffee

@@ -36,13 +36,16 @@ EditorComponent = React.createClass
     className += ' is-focused' if focused
 
     div className: className, style: {fontSize, lineHeight, fontFamily}, tabIndex: -1, onFocus: @onFocus,
-      GutterComponent({editor, renderedRowRange, scrollTop, lineHeight: lineHeightInPixels, @pendingChanges})
+      GutterComponent {
+        editor, renderedRowRange, scrollTop, scrollHeight,
+        lineHeight: lineHeightInPixels, @pendingChanges
+      }
 
       EditorScrollViewComponent {
-        ref: 'scrollView', editor, renderedRowRange, @pendingChanges,
-        @scrollingVertically, showIndentGuide, fontSize, fontFamily,
-        lineHeight: lineHeightInPixels, @cursorsMoved, cursorBlinkPeriod,
-        cursorBlinkResumeDelay, @onInputFocused, @onInputBlurred,
+        ref: 'scrollView', editor, fontSize, fontFamily, showIndentGuide
+        scrollHeight, scrollWidth, lineHeight: lineHeightInPixels,
+        renderedRowRange, @pendingChanges, @scrollingVertically, @cursorsMoved,
+        cursorBlinkPeriod, cursorBlinkResumeDelay, @onInputFocused, @onInputBlurred
       }
 
       ScrollbarComponent

src/editor-scroll-view-component.coffee

@@ -16,12 +16,14 @@ EditorScrollViewComponent = React.createClass
   overflowChangedWhilePaused: false
 
   render: ->
-    {editor, fontSize, fontFamily, lineHeight, showIndentGuide, cursorBlinkPeriod, cursorBlinkResumeDelay} = @props
-    {renderedRowRange, pendingChanges, scrollingVertically, cursorsMoved, onInputFocused, onInputBlurred} = @props
+    {editor, fontSize, fontFamily, lineHeight, showIndentGuide} = @props
+    {scrollHeight, scrollWidth, renderedRowRange, pendingChanges, scrollingVertically} = @props
+    {cursorBlinkPeriod, cursorBlinkResumeDelay, cursorsMoved, onInputFocused, onInputBlurred} = @props
 
     if @isMounted()
       contentStyle =
-        height: editor.getScrollHeight()
+        height: scrollHeight
+        minWidth: scrollWidth
         WebkitTransform: "translate3d(#{-editor.getScrollLeft()}px, #{-editor.getScrollTop()}px, 0)"
 
     div className: 'scroll-view',

src/gutter-component.coffee

@@ -13,14 +13,14 @@ GutterComponent = React.createClass
       @renderLineNumbers() if @isMounted()
 
   renderLineNumbers: ->
-    {editor, renderedRowRange, scrollTop} = @props
+    {editor, renderedRowRange, scrollTop, scrollHeight} = @props
     [startRow, endRow] = renderedRowRange
     charWidth = editor.getDefaultCharWidth()
     lineHeight = editor.getLineHeight()
     maxDigits = editor.getLastBufferRow().toString().length
     style =
       width: charWidth * (maxDigits + 1.5)
-      height: editor.getScrollHeight()
+      height: scrollHeight
       WebkitTransform: "translate3d(0, #{-scrollTop}px, 0)"
 
     lineNumbers = []

static/editor.less

@@ -38,6 +38,7 @@
 
   .scroll-view-content {
     position: relative;
+    width: 100%;
   }
 
   .gutter {