[ruby/reline] Fix a crash when completing empty line

https://github.com/ruby/reline/commit/8226ae7e57

1 files changed, 3 insertions, 1 deletions

diff --git a/lib/reline/line_editor.rb b/lib/reline/line_editor.rb
index 9442bdf5cc..2a1d4b4382 100644
--- a/lib/reline/line_editor.rb
+++ b/lib/reline/line_editor.rb
@@ -1295,8 +1295,10 @@ class Reline::LineEditor
       end
     end
     completed = @completion_journey_data.list[@completion_journey_data.pointer]
-    @line = (@completion_journey_data.preposing + completed + @completion_journey_data.postposing).split("\n")[@line_index]
+    new_line = (@completion_journey_data.preposing + completed + @completion_journey_data.postposing).split("\n")[@line_index]
+    @line = new_line.nil? ? String.new(encoding: @encoding) : new_line
     line_to_pointer = (@completion_journey_data.preposing + completed).split("\n").last
+    line_to_pointer = String.new(encoding: @encoding) if line_to_pointer.nil?
     @cursor_max = calculate_width(@line)
     @cursor = calculate_width(line_to_pointer)
     @byte_pointer = line_to_pointer.bytesize