pack.c: escape and encoding

* pack.c (pack_pack): escape unprintable characters and preserve
  the encoding of warning message.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48307 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Thu Nov  6 23:58:40 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* pack.c (pack_pack): escape unprintable characters and preserve
+	  the encoding of warning message.
+
 Thu Nov  6 23:55:18 2014  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* string.c (sym_printable): QUOTE() should not raise an exception

pack.c

@@ -912,10 +912,19 @@ pack_pack(VALUE ary, VALUE fmt)
 	    }
 	    break;
 
-	  default:
-	    rb_warning("unknown pack directive '%c' in '%s'",
-		type, RSTRING_PTR(fmt));
+	  default: {
+	    char unknown[5];
+	    if (ISPRINT(type)) {
+		unknown[0] = type;
+		unknown[1] = '\0';
+	    }
+	    else {
+		snprintf(unknown, sizeof(unknown), "\\x%.2x", type & 0xff);
+	    }
+	    rb_warning("unknown pack directive '%s' in '% "PRIsVALUE"'",
+		       unknown, fmt);
 	    break;
+	  }
 	}
     }
 

test/ruby/test_pack.rb

@@ -718,5 +718,13 @@ EXPECTED
     assert_warning(/unknown pack directive ',' in ','/) {
       [].pack(",")
     }
+    assert_warning(/\A[ -~]+\Z/) {
+      [].pack("\x7f")
+    }
+    assert_warning(/\A(.* in '\u{3042}'\n)+\z/) {
+      EnvUtil.with_default_external(Encoding::UTF_8) {
+        [].pack("\u{3042}")
+      }
+    }
   end
 end