Suppress crashing when dynamic_prompt_proc returns a broken prompt list

aycabta · JuanitoFatas · aycabta · commit 558f7be16832 · 2021-01-06T03:00:14.000+09:00
Co-authored-by: Juanito Fatas &lt;me@juanitofatas.com&gt;
diff --git a/bin/multiline_repl b/bin/multiline_repl
@@ -22,6 +22,14 @@ opt.on('--dynamic-prompt') {
     }
   }
 }
+opt.on('--broken-dynamic-prompt') {
+  Reline.prompt_proc = proc { |lines|
+    range = lines.size > 1 ? (0..(lines.size - 2)) : (0..0)
+    lines[range].each_with_index.map { |l, i|
+      '[%04d]> ' % i
+    }
+  }
+}
 opt.on('--auto-indent') {
   AutoIndent.new
 }
diff --git a/lib/reline/line_editor.rb b/lib/reline/line_editor.rb
@@ -112,6 +112,7 @@ def simplified_rendering?
           use_cached_prompt_list = true
         end
       end
+      use_cached_prompt_list = false if @rerender_all
       if use_cached_prompt_list
         prompt_list = @cached_prompt_list
       else
@@ -123,6 +124,12 @@ def simplified_rendering?
       prompt_list = prompt_list.map{ |pr| mode_string + pr } if mode_string
       prompt = prompt_list[@line_index]
       prompt = prompt_list[0] if prompt.nil?
+      prompt = prompt_list.last if prompt.nil?
+      if buffer.size > prompt_list.size
+        (buffer.size - prompt_list.size).times do
+          prompt_list << prompt_list.last
+        end
+      end
       prompt_width = calculate_width(prompt, true)
       [prompt, prompt_width, prompt_list]
     else
diff --git a/test/reline/yamatanooroti/test_rendering.rb b/test/reline/yamatanooroti/test_rendering.rb
@@ -450,6 +450,18 @@ def test_prompt_list_caching
       EOC
     end
 
+    def test_broken_prompt_list
+      start_terminal(5, 30, %W{ruby -I#{@pwd}/lib #{@pwd}/bin/multiline_repl --broken-dynamic-prompt}, startup_message: 'Multiline REPL.')
+      write("def hoge\n  3\nend")
+      close
+      assert_screen(<<~EOC)
+        Multiline REPL.
+        [0000]> def hoge
+        [0001]>   3
+        [0001]> end
+      EOC
+    end
+
     def test_enable_bracketed_paste
       omit if Reline::IOGate.win?
       write_inputrc <<~LINES

Original file line number	Diff line number	Diff line change
`@@ -22,6 +22,14 @@ opt.on('--dynamic-prompt') {`
`22`	`22`	`}`
`23`	`23`	`}`
`24`	`24`	`}`
	`25`	`+opt.on('--broken-dynamic-prompt') {`
	`26`	`+ Reline.prompt_proc = proc { \|lines\|`
	`27`	`+ range = lines.size > 1 ? (0..(lines.size - 2)) : (0..0)`
	`28`	`+ lines[range].each_with_index.map { \|l, i\|`
	`29`	`+ '[%04d]> ' % i`
	`30`	`+ }`
	`31`	`+ }`
	`32`	`+}`
`25`	`33`	`opt.on('--auto-indent') {`
`26`	`34`	`AutoIndent.new`
`27`	`35`	`}`