Use IRB.conf[:AUTO_INDENT] setting in multiline mode

lib/irb.rb

@@ -491,6 +491,8 @@ module IRB
         end
       end
 
+      @scanner.set_auto_indent(@context) if @context.auto_indent_mode
+
       @scanner.each_top_level_statement do |line, line_no|
         signal_status(:IN_EVAL) do
           begin

lib/irb/input-method.rb

@@ -255,7 +255,7 @@ module IRB
       Reline.input = @stdin
       Reline.output = @stdout
       Reline.prompt_proc = @prompt_proc
-      Reline.auto_indent_proc = @auto_indent_proc
+      Reline.auto_indent_proc = @auto_indent_proc if @auto_indent_proc
       if l = readmultiline(@prompt, false, &@check_termination_proc)
         HISTORY.push(l) if !l.empty?
         @line[@line_no += 1] = l + "\n"

lib/irb/ruby-lex.rb

@@ -53,7 +53,26 @@ class RubyLex
         result
       end
     end
-    if @io.respond_to?(:auto_indent)
+    if p.respond_to?(:call)
+      @input = p
+    elsif block_given?
+      @input = block
+    else
+      @input = Proc.new{@io.gets}
+    end
+  end
+
+  def set_prompt(p = nil, &block)
+    p = block if block_given?
+    if p.respond_to?(:call)
+      @prompt = p
+    else
+      @prompt = Proc.new{print p}
+    end
+  end
+
+  def set_auto_indent(context)
+    if @io.respond_to?(:auto_indent) and context.auto_indent_mode
       @io.auto_indent do |lines, line_index, byte_pointer, is_newline|
         if is_newline
           md = lines[line_index - 1].match(/(\A +)/)
@@ -82,22 +101,6 @@ class RubyLex
         end
       end
     end
-    if p.respond_to?(:call)
-      @input = p
-    elsif block_given?
-      @input = block
-    else
-      @input = Proc.new{@io.gets}
-    end
-  end
-
-  def set_prompt(p = nil, &block)
-    p = block if block_given?
-    if p.respond_to?(:call)
-      @prompt = p
-    else
-      @prompt = Proc.new{print p}
-    end
   end
 
   def check_state(code)