Index: obmalloc.c
===================================================================
RCS file: /cvsroot/python/python/dist/src/Objects/obmalloc.c,v
retrieving revision 2.50
diff -c -r2.50 obmalloc.c
*** obmalloc.c	23 Nov 2002 09:13:40 -0000	2.50
--- obmalloc.c	3 Apr 2003 03:00:48 -0000
***************
*** 1124,1129 ****
--- 1124,1130 ----
  {
  	const uchar *q = (const uchar *)p;
  	const uchar *tail;
+ 	int tail_reachable = 0; /* can we dereference tail without segfault */
  	ulong nbytes, serial;
  	int i;
  
***************
*** 1161,1188 ****
  
  	tail = q + nbytes;
  	fprintf(stderr, "    The 4 pad bytes at tail=%p are ", tail);
! 	if (tail[0] == FORBIDDENBYTE &&
! 	    tail[1] == FORBIDDENBYTE &&
! 	    tail[2] == FORBIDDENBYTE &&
! 	    tail[3] == FORBIDDENBYTE) {
! 		fputs("FORBIDDENBYTE, as expected.\n", stderr);
  	}
! 	else {
! 		fprintf(stderr, "not all FORBIDDENBYTE (0x%02x):\n",
! 			FORBIDDENBYTE);
! 		for (i = 0; i < 4; ++i) {
! 			const uchar byte = tail[i];
! 			fprintf(stderr, "        at tail+%d: 0x%02x",
! 				i, byte);
! 			if (byte != FORBIDDENBYTE)
! 				fputs(" *** OUCH", stderr);
! 			fputc('\n', stderr);
  		}
- 	}
  
! 	serial = read4(tail+4);
! 	fprintf(stderr, "    The block was made by call #%lu to "
! 	                "debug malloc/realloc.\n", serial);
  
  	if (nbytes > 0) {
  		int i = 0;
--- 1162,1202 ----
  
  	tail = q + nbytes;
  	fprintf(stderr, "    The 4 pad bytes at tail=%p are ", tail);
! #ifdef MS_WINDOWS
! 	_try {
! #endif /* MS_WINDOWS */
! 	tail_reachable = *tail ? 1 : 1; /* if we don't die, it is reachable! */
! #ifdef MS_WINDOWS
! 	} _except(1) {
! 		/* tail_reachable remains 0 */
  	}
! #endif /* MS_WINDOWS */
! 	if (tail_reachable) {
! 		if (tail[0] == FORBIDDENBYTE &&
! 			tail[1] == FORBIDDENBYTE &&
! 			tail[2] == FORBIDDENBYTE &&
! 			tail[3] == FORBIDDENBYTE) {
! 			fputs("FORBIDDENBYTE, as expected.\n", stderr);
! 		}
! 		else {
! 			fprintf(stderr, "not all FORBIDDENBYTE (0x%02x):\n",
! 				FORBIDDENBYTE);
! 			for (i = 0; i < 4; ++i) {
! 				const uchar byte = tail[i];
! 				fprintf(stderr, "        at tail+%d: 0x%02x",
! 					i, byte);
! 				if (byte != FORBIDDENBYTE)
! 					fputs(" *** OUCH", stderr);
! 				fputc('\n', stderr);
! 			}
  		}
  
! 		serial = read4(tail+4);
! 		fprintf(stderr, "    The block was made by call #%lu to "
! 						"debug malloc/realloc.\n", serial);
! 	} else {
! 		fprintf(stderr, "INVALID\n");
! 	}
  
  	if (nbytes > 0) {
  		int i = 0;
***************
*** 1194,1200 ****
  			++q;
  		}
  		/* and up to 8 at the end */
! 		if (q < tail) {
  			if (tail - q > 8) {
  				fputs(" ...", stderr);
  				q = tail - 8;
--- 1208,1214 ----
  			++q;
  		}
  		/* and up to 8 at the end */
! 		if (q < tail && tail_reachable) {
  			if (tail - q > 8) {
  				fputs(" ...", stderr);
  				q = tail - 8;