String#concat: Try to convert when not string

2 files changed, 18 insertions, 7 deletions

diff --git a/mrbgems/mruby-string-ext/src/string.c b/mrbgems/mruby-string-ext/src/string.c
index 4c22f40c7..9dc1aeafc 100644
--- a/mrbgems/mruby-string-ext/src/string.c
+++ b/mrbgems/mruby-string-ext/src/string.c
@@ -134,6 +134,8 @@ mrb_str_swapcase(mrb_state *mrb, mrb_value self)
   return str;
 }
 
+static mrb_value mrb_fixnum_chr(mrb_state *mrb, mrb_value num);
+
 /*
  *  call-seq:
  *     str << integer       -> str
@@ -153,7 +155,12 @@ static mrb_value
 mrb_str_concat2(mrb_state *mrb, mrb_value self)
 {
   mrb_value str;
-  mrb_get_args(mrb, "S", &str);
+
+  mrb_get_args(mrb, "o", &str);
+  if (mrb_fixnum_p(str))
+    str = mrb_fixnum_chr(mrb, str);
+  else
+    str = mrb_string_type(mrb, str);
   mrb_str_concat(mrb, self, str);
   return self;
 }
diff --git a/mrbgems/mruby-string-ext/test/string.rb b/mrbgems/mruby-string-ext/test/string.rb
index 24bc859d8..da39bd8e9 100644
--- a/mrbgems/mruby-string-ext/test/string.rb
+++ b/mrbgems/mruby-string-ext/test/string.rb
@@ -122,12 +122,16 @@ assert('String#swapcase!') do
 end
 
 assert('String#concat') do
-  s = "Hello "
-  s.concat "World!"
-  t = "Hello "
-  t << "World!"
-  assert_equal "Hello World!", t
-  assert_equal "Hello World!", s
+  assert_equal "Hello World!", "Hello " << "World" << 33
+  assert_equal "Hello World!", "Hello ".concat("World").concat(33)
+
+  o = Object.new
+  def o.to_str
+    "to_str"
+  end
+  assert_equal "hi to_str", "hi " << o
+
+  assert_raise(TypeError) { "".concat(Object.new) }
 end
 
 assert('String#casecmp') do