[ruby/reline] Correct padding space calculation

fix https://github.com/ruby/irb/issues/308

This bug occurred when `dialog.width - calculate_width(s, true)` was negative.

When `dialog.width` is shorter than `old_dialog.width`, it calculates how much padding it has to do. However, there are cases where `s` is longer than `dialog.width`, as in the issue. In that case, `padding_space_with_escape_sequences` will crash.

Here, `old_dialog.width` is longer than `dialog.width`, so I changed the padding width to `old_dialog.width - dialog.width`.

https://github.com/ruby/reline/commit/c581c31e0f

2 files changed, 37 insertions, 0 deletions

diff --git a/test/reline/yamatanooroti/multiline_repl b/test/reline/yamatanooroti/multiline_repl
index da886b8f06..1f2a023724 100755
--- a/test/reline/yamatanooroti/multiline_repl
+++ b/test/reline/yamatanooroti/multiline_repl
@@ -137,6 +137,28 @@ opt.on('--autocomplete-super-long') {
     2000.times.map{ s = "Str_#{c}"; c.succ!; s }.select{ |c| c.start_with?(target) }
   }
 }
+
+opt.on('--autocomplete-width-long') {
+  Reline.autocompletion = true
+  Reline.completion_proc = lambda { |target, preposing = nil, postposing = nil|
+    %w{
+        remove_instance_variable
+        respond_to?
+        ruby2_keywords
+        rand
+        readline
+        readlines
+        require
+        require_relative
+        raise
+        respond_to_missing?
+        redo
+        rescue
+        retry
+        return
+    }.select{ |c| c.start_with?(target) }
+  }
+}
 opt.parse!(ARGV)
 
 begin
diff --git a/test/reline/yamatanooroti/test_rendering.rb b/test/reline/yamatanooroti/test_rendering.rb
index e1dde83589..f68b614327 100644
--- a/test/reline/yamatanooroti/test_rendering.rb
+++ b/test/reline/yamatanooroti/test_rendering.rb
@@ -1172,6 +1172,21 @@ begin
       EOC
     end
 
+    def test_autocomplete_old_dialog_width_greater_than_dialog_width
+      start_terminal(40, 40, %W{ruby -I#{@pwd}/lib #{@pwd}/test/reline/yamatanooroti/multiline_repl --autocomplete-width-long}, startup_message: 'Multiline REPL.')
+      write("0+ \n12345678901234")
+      write("\C-p")
+      write("r")
+      write("a")
+      close
+      assert_screen(<<~'EOC')
+        Multiline REPL.
+        prompt> 0+ ra
+        prompt> 123rand 901234
+                   raise
+      EOC
+    end
+
     def write_inputrc(content)
       File.open(@inputrc_file, 'w') do |f|
         f.write content