* strftime.c (NEEDS): avoid SEGV due to integer overflow in sparc-solaris2.10

and i686-linux.  fix [Bug #4456] [ruby-dev:43284]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@32757 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Sat Jul 30 22:35:50 2011  Naohisa Goto  <ngotogenome@gmail.com>
+
+	* strftime.c (NEEDS): avoid SEGV due to integer overflow in
+	  sparc-solaris2.10 and i686-linux.  fix [Bug #4456] [ruby-dev:43284]
+
 Sat Jul 30 17:26:26 2011  Masaki Suketa <masaki.suketa@nifty.ne.jp>
 
 	* test/win32ole/test_win32ole_variant.rb: use skip method to skip the test.

strftime.c

@@ -210,7 +210,7 @@ rb_strftime_with_timespec(char *s, size_t maxsize, const char *format, const str
 			if (precision > 0 || flags & (BIT_OF(LOCALE_E)|BIT_OF(LOCALE_O))) \
 				goto unknown; \
 		} while (0)
-#define NEEDS(n) do if (s + (n) >= endp - 1) goto err; while (0)
+#define NEEDS(n) do if (s >= endp || (n) >= endp - s - 1) goto err; while (0)
 #define FILL_PADDING(i) do { \
 	if (!(flags & BIT_OF(LEFT)) && precision > (i)) { \
 		NEEDS(precision); \