symbol.c: more informative error message

* symbol.c (sym_check_asciionly): more informative error message
  with the encoding name and the inspected content.
  [ruby-core:73398] [Feature #12016]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53650 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,9 @@
+Mon Jan 25 15:55:30 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* symbol.c (sym_check_asciionly): more informative error message
+	  with the encoding name and the inspected content.
+	  [ruby-core:73398] [Feature #12016]
+
 Mon Jan 25 09:38:26 2016  SHIBATA Hiroshi  <hsbt@ruby-lang.org>
 
 	* test/ruby/test_string.rb: added testcase for next!, succ and succ!

symbol.c

@@ -430,7 +430,8 @@ sym_check_asciionly(VALUE str)
     if (!rb_enc_asciicompat(rb_enc_get(str))) return FALSE;
     switch (rb_enc_str_coderange(str)) {
       case ENC_CODERANGE_BROKEN:
-	rb_raise(rb_eEncodingError, "invalid encoding symbol");
+	rb_raise(rb_eEncodingError, "invalid symbol in encoding %s :%+"PRIsVALUE,
+		 rb_enc_name(rb_enc_get(str)), str);
       case ENC_CODERANGE_7BIT:
 	return TRUE;
     }

test/ruby/test_symbol.rb

@@ -262,7 +262,7 @@ class TestSymbol < Test::Unit::TestCase
     assert_equal(Encoding::US_ASCII, "$-A".force_encoding("iso-8859-15").intern.encoding)
     assert_equal(Encoding::US_ASCII, "foobar~!".force_encoding("iso-8859-15").intern.encoding)
     assert_equal(Encoding::UTF_8, "\u{2192}".intern.encoding)
-    assert_raise(EncodingError) {"\xb0a".force_encoding("utf-8").intern}
+    assert_raise_with_message(EncodingError, /\\xb0/i) {"\xb0a".force_encoding("utf-8").intern}
   end
 
   def test_singleton_method