range.c: Fix an exception message in rb_range_beg_len

[Bug #17271]

range.c

@@ -1332,7 +1332,7 @@ rb_range_values(VALUE range, VALUE *begp, VALUE *endp, int *exclp)
 VALUE
 rb_range_beg_len(VALUE range, long *begp, long *lenp, long len, int err)
 {
-    long beg, end, origbeg, origend;
+    long beg, end;
     VALUE b, e;
     int excl;
 
@@ -1341,8 +1341,6 @@ rb_range_beg_len(VALUE range, long *begp, long *lenp, long len, int err)
     beg = NIL_P(b) ? 0 : NUM2LONG(b);
     end = NIL_P(e) ? -1 : NUM2LONG(e);
     if (NIL_P(e)) excl = 0;
-    origbeg = beg;
-    origend = end;
     if (beg < 0) {
 	beg += len;
 	if (beg < 0)
@@ -1368,8 +1366,7 @@ rb_range_beg_len(VALUE range, long *begp, long *lenp, long len, int err)
 
   out_of_range:
     if (err) {
-	rb_raise(rb_eRangeError, "%ld..%s%ld out of range",
-		 origbeg, excl ? "." : "", origend);
+	rb_raise(rb_eRangeError, "%+"PRIsVALUE" out of range", range);
     }
     return Qnil;
 }

test/ruby/test_array.rb

@@ -2381,6 +2381,9 @@ class TestArray < Test::Unit::TestCase
     assert_raise(ArgumentError) { [0].freeze[0, 0, 0] = 0 }
     assert_raise(TypeError) { [0][:foo] = 0 }
     assert_raise(FrozenError) { [0].freeze[:foo] = 0 }
+
+    # [Bug #17271]
+    assert_raise_with_message(RangeError, "-7.. out of range") { [*0..5][-7..] = 1 }
   end
 
   def test_first2