3 files changed, 30 insertions, 15 deletions

diff --git a/ChangeLog b/ChangeLog
index 36eca2c92d..732133161a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Mon Jul 30 11:16:40 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* bignum.c (rb_big_aref): check for Bignum index range.
+	 [ruby-dev:31271]
+
 Sat Jul 28 09:35:41 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* ext/digest/lib/digest.rb (Digest::self.const_missing): avoid
diff --git a/bignum.c b/bignum.c
index f5a47871d3..38717e4257 100644
--- a/bignum.c
+++ b/bignum.c
@@ -2151,29 +2151,39 @@ rb_big_aref(x, y)
     VALUE x, y;
 {
     BDIGIT *xds;
-    int shift;
-    long s1, s2;
+    BDIGIT_DBL num;
+    unsigned long shift;
+    long i, s1, s2;
 
     if (TYPE(y) == T_BIGNUM) {
-	if (!RBIGNUM(y)->sign || RBIGNUM(x)->sign)
+	if (!RBIGNUM(y)->sign)
 	    return INT2FIX(0);
-	return INT2FIX(1);
+	if (RBIGNUM(bigtrunc(y))->len > SIZEOF_LONG/SIZEOF_BDIGITS) {
+	  out_of_range:
+	    return RBIGNUM(x)->sign ? INT2FIX(0) : INT2FIX(1);
+	}
+	shift = big2ulong(y, "long", Qfalse);
+    }
+    else {
+	i = NUM2LONG(y);
+	if (i < 0) return INT2FIX(0);
+	shift = (VALUE)i;
     }
-    shift = NUM2INT(y);
-    if (shift < 0) return INT2FIX(0);
     s1 = shift/BITSPERDIG;
     s2 = shift%BITSPERDIG;
 
+    if (s1 >= RBIGNUM(x)->len) goto out_of_range;
     if (!RBIGNUM(x)->sign) {
-	if (s1 >= RBIGNUM(x)->len) return INT2FIX(1);
-	x = rb_big_clone(x);
-	get2comp(x);
+	xds = BDIGITS(x);
+	i = 0; num = 1;
+	while (num += ~xds[i], ++i <= s1) {
+	    num = BIGDN(num);
+	}
     }
     else {
-	if (s1 >= RBIGNUM(x)->len) return INT2FIX(0);
+	num = BDIGITS(x)[s1];
     }
-    xds = BDIGITS(x);
-    if (xds[s1] & (1<<s2))
+    if (num & ((BDIGIT_DBL)1<<s2))
 	return INT2FIX(1);
     return INT2FIX(0);
 }
diff --git a/version.h b/version.h
index 20cf32d4e7..54ac7f32fb 100644
--- a/version.h
+++ b/version.h
@@ -1,7 +1,7 @@
 #define RUBY_VERSION "1.8.6"
-#define RUBY_RELEASE_DATE "2007-07-28"
+#define RUBY_RELEASE_DATE "2007-07-30"
 #define RUBY_VERSION_CODE 186
-#define RUBY_RELEASE_CODE 20070728
+#define RUBY_RELEASE_CODE 20070730
 #define RUBY_PATCHLEVEL 5000
 
 #define RUBY_VERSION_MAJOR 1
@@ -9,7 +9,7 @@
 #define RUBY_VERSION_TEENY 6
 #define RUBY_RELEASE_YEAR 2007
 #define RUBY_RELEASE_MONTH 7
-#define RUBY_RELEASE_DAY 28
+#define RUBY_RELEASE_DAY 30
 
 #ifdef RUBY_EXTERN
 RUBY_EXTERN const char ruby_version[];