Hi,

In message "Re: Symbols overlap ordinary objects, especially on OS X (Was: Re: Problem with weak references on OS X 10.3)"
    on Thu, 23 Feb 2006 10:26:00 +0900, Mauricio Fernandez <mfp / acm.org> writes:

|On my system the values returned by malloc start around 0xb7d00000 (when using brk)
|so I can hardly create enough symbols to force a collision, but I can get
|a crash on Linux with the following:

Since all symbol values have their second LSB set, they should not
conflict with ordinary object values on an aligned memory allocator.
At least on Linux system, the problem was caused by signedness issue
of the symbol conversion.  I'd like to know if the following patch,
that worked on Linux system, also work on MacOS X.

							matz.

--- ruby.h	5 Feb 2006 15:43:10 -0000	1.97.2.11
+++ ruby.h	26 Feb 2006 15:43:22 -0000
@@ -169,3 +169,3 @@ VALUE rb_ull2inum _((unsigned LONG_LONG)
 #define ID2SYM(x) ((VALUE)(((long)(x))<<8|SYMBOL_FLAG))
-#define SYM2ID(x) RSHIFT((long)x,8)
+#define SYM2ID(x) RSHIFT((unsigned long)x,8)