encoding.c: validate index

* encoding.c (rb_enc_set_index, rb_enc_associate_index): validate
  argument encoding index.
* include/ruby/encoding.h (ENCODING_SET): use rb_enc_set_index()
  instead of setting inlined bits directly.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@41739 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,4 +1,10 @@
-Tue Jul  2 17:22:12 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+Tue Jul  2 17:22:16 2013  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* encoding.c (rb_enc_set_index, rb_enc_associate_index): validate
+	  argument encoding index.
+
+	* include/ruby/encoding.h (ENCODING_SET): use rb_enc_set_index()
+	  instead of setting inlined bits directly.
 
 	* encoding.c (rb_enc_init): register preserved indexes.
 

encoding.c

@@ -142,6 +142,25 @@ must_encoding(VALUE enc)
     return index;
 }
 
+static rb_encoding *
+must_encindex(int index)
+{
+    rb_encoding *enc = rb_enc_from_index(index);
+    if (!enc) {
+	rb_raise(rb_eEncodingError, "encoding index out of bound: %d",
+		 index);
+    }
+    if (ENC_TO_ENCINDEX(enc) != index) {
+	rb_raise(rb_eEncodingError, "wrong encoding index %d for %s (expected %d)",
+		 index, rb_enc_name(enc), ENC_TO_ENCINDEX(enc));
+    }
+    if (enc_autoload_p(enc) && enc_autoload(enc) == -1) {
+	rb_loaderror("failed to load encoding (%s)",
+		     rb_enc_name(enc));
+    }
+    return enc;
+}
+
 int
 rb_to_encoding_index(VALUE enc)
 {
@@ -736,12 +755,15 @@ void
 rb_enc_set_index(VALUE obj, int idx)
 {
     rb_check_frozen(obj);
+    must_encindex(idx);
     enc_set_index(obj, idx);
 }
 
 VALUE
 rb_enc_associate_index(VALUE obj, int idx)
 {
+    rb_encoding *enc;
+
 /*    enc_check_capable(obj);*/
     rb_check_frozen(obj);
     if (rb_enc_get_index(obj) == idx)
@@ -749,8 +771,9 @@ rb_enc_associate_index(VALUE obj, int idx)
     if (SPECIAL_CONST_P(obj)) {
 	rb_raise(rb_eArgError, "cannot set encoding");
     }
+    enc = must_encindex(idx);
     if (!ENC_CODERANGE_ASCIIONLY(obj) ||
-	!rb_enc_asciicompat(rb_enc_from_index(idx))) {
+	!rb_enc_asciicompat(enc)) {
 	ENC_CODERANGE_CLEAR(obj);
     }
     enc_set_index(obj, idx);

include/ruby/encoding.h

@@ -32,14 +32,7 @@ RUBY_SYMBOL_EXPORT_BEGIN
     RBASIC(obj)->flags &= ~ENCODING_MASK;\
     RBASIC(obj)->flags |= (VALUE)(i) << ENCODING_SHIFT;\
 } while (0)
-#define ENCODING_SET(obj,i) do {\
-    VALUE rb_encoding_set_obj = (obj); \
-    int encoding_set_enc_index = (i); \
-    if (encoding_set_enc_index < ENCODING_INLINE_MAX) \
-        ENCODING_SET_INLINED(rb_encoding_set_obj, encoding_set_enc_index); \
-    else \
-        rb_enc_set_index(rb_encoding_set_obj, encoding_set_enc_index); \
-} while (0)
+#define ENCODING_SET(obj,i) rb_enc_set_index((obj), (i))
 
 #define ENCODING_GET_INLINED(obj) (int)((RBASIC(obj)->flags & ENCODING_MASK)>>ENCODING_SHIFT)
 #define ENCODING_GET(obj) \