Editor.renderedLines' css width is set to 100% when editor.maxScreenLineLength() is less than Editor.scrollView's width

spec/app/editor-spec.coffee

@@ -1241,9 +1241,11 @@ describe "Editor", ->
           expect(editor.renderedLines.find(".line:last").text()).toBe buffer.lineForRow(6)
 
       it "increases the width of the rendered lines element to be either the width of the longest line or the width of the scrollView (whichever is longer)", ->
+        maxLineLength = editor.maxScreenLineLength()
+        setEditorWidthInChars(editor, maxLineLength)
         widthBefore = editor.renderedLines.width()
         expect(widthBefore).toBe editor.scrollView.width()
-        buffer.change([[12,0], [12,0]], [1..50].join(''))
+        buffer.change([[12,0], [12,0]], [1..maxLineLength*2].join(''))
         expect(editor.renderedLines.width()).toBeGreaterThan widthBefore
 
     describe "when lines are removed", ->
@@ -1251,6 +1253,15 @@ describe "Editor", ->
         editor.attachToDom(heightInLines: 5)
         spyOn(editor, "scrollTo")
 
+      it "sets the rendered screen line's width to either the max line length or the scollView's width (whichever is greater)", ->
+        maxLineLength = editor.maxScreenLineLength()
+        setEditorWidthInChars(editor, maxLineLength)
+        buffer.change([[12,0], [12,0]], [1..maxLineLength*2].join(''))
+        expect(editor.renderedLines.width()).toBeGreaterThan editor.scrollView.width()
+        widthBefore = editor.renderedLines.width()
+        buffer.delete([[12, 0], [12, Infinity]])
+        expect(editor.renderedLines.width()).toBe editor.scrollView.width()
+
       describe "when the change the precedes the first rendered row", ->
         it "removes rendered lines to account for upstream change", ->
           editor.scrollToBottom()
@@ -1321,13 +1332,6 @@ describe "Editor", ->
 
           expect(editor.find('.line').length).toBe 7
 
-      it "sets the rendered screen line's width to either the max line length or the scollView's width (whichever is greater)", ->
-        buffer.change([[12,0], [12,0]], [1..100].join(''))
-        expect(editor.renderedLines.width()).toBeGreaterThan editor.scrollView.width()
-        widthBefore = editor.renderedLines.width()
-        buffer.delete([[12, 0], [12, Infinity]])
-        expect(editor.renderedLines.width()).toBe editor.scrollView.width()
-
     describe "when folding leaves less then a screen worth of text (regression)", ->
       it "renders lines properly", ->
         editor.lineOverdraw = 1

spec/spec-helper.coffee

@@ -125,6 +125,7 @@ window.tokensText = (tokens) ->
 
 window.setEditorWidthInChars = (editor, widthInChars, charWidth=editor.charWidth) ->
   editor.width(charWidth * widthInChars + editor.renderedLines.position().left)
+  $(window).trigger 'resize' # update width of editor's on-screen lines
 
 window.setEditorHeightInLines = (editor, heightInChars, charHeight=editor.lineHeight) ->
   editor.height(charHeight * heightInChars + editor.renderedLines.position().top)

src/app/editor.coffee

@@ -657,7 +657,7 @@ class Editor extends View
     if width > @scrollView.width()
       @renderedLines.width(width)
     else
-      @renderedLines.width(@scrollView.width())
+      @renderedLines.width("inherit")
 
   handleScrollHeightChange: ->
     scrollHeight = @lineHeight * @screenLineCount()

static/editor.css

@@ -67,6 +67,7 @@
   position: relative;
   display: table;
   height: 100%;
+  width: 100%;
 }
 
 .editor .line {