* bignum.c (rb_big_pow): refine overflow check. [ruby-dev:31242]

shyouhei · shyouhei · commit c204c6b71bad · 2007-08-22T01:32:19.000Z
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_1_8_6@13186 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
diff --git a/ChangeLog b/ChangeLog
@@ -1,3 +1,7 @@
+Wed Aug 22 10:29:45 2007  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* bignum.c (rb_big_pow): refine overflow check.  [ruby-dev:31242]
+
 Wed Aug 22 10:26:59 2007  Yukihiro Matsumoto  <matz@ruby-lang.org>
 
 	* time.c (time_succ): Time#succ should return a time object in the
diff --git a/bignum.c b/bignum.c
@@ -1646,8 +1646,10 @@ rb_big_pow(x, y)
 	yy = FIX2LONG(y);
 	if (yy > 0) {
 	    VALUE z = x;
+	    const long BIGLEN_LIMIT = 1024*1024 / SIZEOF_BDIGITS;
 
-	    if (RBIGNUM(x)->len * SIZEOF_BDIGITS * yy > 1024*1024) {
+	    if ((RBIGNUM(x)->len > BIGLEN_LIMIT) ||
+		(RBIGNUM(x)->len > BIGLEN_LIMIT / yy)) {
 		rb_warn("in a**b, b may be too big");
 		d = (double)yy;
 		break;
diff --git a/version.h b/version.h
@@ -2,7 +2,7 @@
 #define RUBY_RELEASE_DATE "2007-08-22"
 #define RUBY_VERSION_CODE 186
 #define RUBY_RELEASE_CODE 20070822
-#define RUBY_PATCHLEVEL 69
+#define RUBY_PATCHLEVEL 70
 
 #define RUBY_VERSION_MAJOR 1
 #define RUBY_VERSION_MINOR 8
