Fix irb-1.9.0 crash on {}. completion

lib/irb/completion.rb

@@ -210,16 +210,16 @@ def retrieve_completion_data(input, bind:, doc_namespace:)
         end
 
       when /^([^\}]*\})\.([^.]*)$/
-        # Proc or Hash
+        # Hash or Proc
         receiver = $1
         message = $2
 
         if doc_namespace
-          ["Proc.#{message}", "Hash.#{message}"]
+          ["Hash.#{message}", "Proc.#{message}"]
         else
-          proc_candidates = Proc.instance_methods.collect{|m| m.to_s}
           hash_candidates = Hash.instance_methods.collect{|m| m.to_s}
-          select_message(receiver, message, proc_candidates | hash_candidates)
+          proc_candidates = Proc.instance_methods.collect{|m| m.to_s}
+          select_message(receiver, message, hash_candidates | proc_candidates)
         end
 
       when /^(:[^:.]+)$/

lib/irb/input-method.rb

@@ -312,6 +312,9 @@ def show_doc_dialog_proc
         return nil if result.nil? or pointer.nil? or pointer < 0
 
         name = doc_namespace.call(result[pointer])
+        # Use first one because document dialog does not support multiple namespaces.
+        name = name.first if name.is_a?(Array)
+
         show_easter_egg = name&.match?(/\ARubyVM/) && !ENV['RUBY_YES_I_AM_NOT_A_NORMAL_USER']
 
         options = {}

test/irb/test_completion.rb

@@ -37,11 +37,11 @@ def test_complete_array
       def test_complete_hash_and_proc
         # hash
         assert_include(completion_candidates("{}.an", binding), "{}.any?")
-        assert_equal(["Proc.any?", "Hash.any?"], doc_namespace("{}.any?", binding))
+        assert_equal(["Hash.any?", "Proc.any?"], doc_namespace("{}.any?", binding))
 
         # proc
         assert_include(completion_candidates("{}.bin", binding), "{}.binding")
-        assert_equal(["Proc.binding", "Hash.binding"], doc_namespace("{}.binding", binding))
+        assert_equal(["Hash.binding", "Proc.binding"], doc_namespace("{}.binding", binding))
       end
 
       def test_complete_numeric

test/irb/yamatanooroti/test_rendering.rb

@@ -203,6 +203,21 @@ def test_symbol_with_backtick
     EOC
   end
 
+  def test_autocomplete_with_multiple_doc_namespaces
+    write_irbrc <<~'LINES'
+      puts 'start IRB'
+    LINES
+    start_terminal(4, 40, %W{ruby -I#{@pwd}/lib #{@pwd}/exe/irb}, startup_message: 'start IRB')
+    write("{}.__id_")
+    write("\C-i")
+    close
+    assert_screen(<<~EOC)
+      start IRB
+      irb(main):001> {}.__id__
+                      }.__id__
+    EOC
+  end
+
   def test_autocomplete_with_showdoc_in_gaps_on_narrow_screen_right
     rdoc_dir = File.join(@tmpdir, 'rdoc')
     system("bundle exec rdoc -r -o #{rdoc_dir}")