Fix crasher when pressing delete at end of doc

plugins/edit_view/features/soft_tabs.feature

@@ -281,4 +281,13 @@ Feature: Soft and hard tabs
     And I replace the contents with "Hi\nHo"
     And I move the cursor to 3
     And I press the Left key in the edit tab
-    Then the contents should be "Hi<c>\nHo"
+    Then the contents should be "Hi<c>\nHo"
+
+  Scenario: Shouldn't die if the cursor is at the end of the document
+    When I open a new edit tab
+    And tabs are soft, 4 spaces
+    And I replace the contents with ""
+    And I move the cursor to 0
+    And I press the Delete key in the edit tab
+    Then the cursor should be at 0
+

plugins/edit_view/lib/edit_view/actions/arrow_keys.rb

@@ -78,6 +78,7 @@ def self.handle(edit_view, modifiers)
           return if (modifiers & %w(Alt Cmd Ctrl)).any?
           return if edit_view.document.block_selection_mode?
           doc = edit_view.document
+
           if modifiers.include?("Shift")
             old_selection_offset = doc.selection_offset
             doc.set_selection_range(move_right_offset(edit_view), old_selection_offset)
@@ -88,7 +89,12 @@ def self.handle(edit_view, modifiers)
 
         def self.move_right_offset(edit_view)
           doc = edit_view.document
-          return doc.length - 1 if doc.cursor_offset == doc.length - 1
+          [move_right_offset1(edit_view), doc.length].min
+        end
+
+        def self.move_right_offset1(edit_view)
+          doc = edit_view.document
+          return doc.length if doc.cursor_offset == doc.length - 1
           if edit_view.soft_tabs?
             line = doc.get_line(doc.cursor_line)
             width = edit_view.tab_width