numeric.c: refine error message

* numeric.c (rb_num_get_rounding_option): refine error message at
  invalid rounding mode.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56854 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 20 insertions, 8 deletions

diff --git a/numeric.c b/numeric.c
index 6707ec39f7..e82f0bd518 100644
--- a/numeric.c
+++ b/numeric.c
@@ -189,28 +189,34 @@ rb_num_get_rounding_option(VALUE opts)
 {
     static ID round_kwds[1];
     VALUE rounding;
+    VALUE str;
     const char *s;
-    long l;
 
     if (!NIL_P(opts)) {
 	if (!round_kwds[0]) {
 	    round_kwds[0] = rb_intern_const("half");
 	}
 	if (!rb_get_kwargs(opts, round_kwds, 0, 1, &rounding)) goto noopt;
-	if (SYMBOL_P(rounding)) rounding = rb_sym2str(rounding);
-	s = StringValueCStr(rounding);
-	l = RSTRING_LEN(rounding);
-	switch (l) {
+	if (SYMBOL_P(rounding)) {
+	    str = rb_sym2str(rounding);
+	}
+	else if (!RB_TYPE_P(str = rounding, T_STRING)) {
+	    str = rb_check_string_type(rounding);
+	    if (NIL_P(str)) goto invalid;
+	}
+	s = RSTRING_PTR(str);
+	switch (RSTRING_LEN(str)) {
 	  case 2:
-	    if (strncasecmp(s, "up", 2) == 0)
+	    if (rb_memcicmp(s, "up", 2) == 0)
 		return RUBY_NUM_ROUND_HALF_UP;
 	    break;
 	  case 4:
-	    if (strncasecmp(s, "even", 4) == 0)
+	    if (rb_memcicmp(s, "even", 4) == 0)
 		return RUBY_NUM_ROUND_HALF_EVEN;
 	    break;
 	}
-	rb_raise(rb_eArgError, "unknown rounding mode: %"PRIsVALUE, rounding);
+      invalid:
+	rb_raise(rb_eArgError, "invalid rounding mode: % "PRIsVALUE, rounding);
     }
   noopt:
     return RUBY_NUM_ROUND_DEFAULT;
diff --git a/test/ruby/test_float.rb b/test/ruby/test_float.rb
index f2989e4f5b..74744bfaa2 100644
--- a/test/ruby/test_float.rb
+++ b/test/ruby/test_float.rb
@@ -701,6 +701,12 @@ class TestFloat < Test::Unit::TestCase
     assert_equal(-7.1364, -7.1364499.round(4, half: :up))
   end
 
+  def test_round_half_invalid
+    assert_raise_with_message(ArgumentError, /xxx/) {
+      1.0.round(half: "\0xxx")
+    }
+  end
+
   def test_Float
     assert_in_delta(0.125, Float("0.1_2_5"), 0.00001)
     assert_in_delta(0.125, "0.1_2_5__".to_f, 0.00001)