===================================================================
RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/awk/lex.c,v
retrieving revision 1.19
retrieving revision 1.20
diff -c -r1.19 -r1.20
*** src/usr.bin/awk/lex.c	2020/06/10 21:05:50	1.19
--- src/usr.bin/awk/lex.c	2020/06/13 01:19:55	1.20
***************
*** 1,4 ****
! /*	$OpenBSD: lex.c,v 1.19 2020/06/10 21:05:50 millert Exp $	*/
  /****************************************************************
  Copyright (C) Lucent Technologies 1997
  All Rights Reserved
--- 1,4 ----
! /*	$OpenBSD: lex.c,v 1.20 2020/06/13 01:19:55 millert Exp $	*/
  /****************************************************************
  Copyright (C) Lucent Technologies 1997
  All Rights Reserved
***************
*** 524,535 ****
  	int c, openclass = 0;
  	static char *buf = NULL;
  	static int bufsz = 500;
! 	char *bp;
  
  	if (buf == NULL && (buf = malloc(bufsz)) == NULL)
  		FATAL("out of space for rex expr");
  	bp = buf;
! 	for ( ; ((c = input()) != '/' || openclass == 1) && c != 0; ) {
  		if (!adjbuf(&buf, &bufsz, bp-buf+3, 500, &bp, "regexpr"))
  			FATAL("out of space for reg expr %.10s...", buf);
  		if (c == '\n') {
--- 524,535 ----
  	int c, openclass = 0;
  	static char *buf = NULL;
  	static int bufsz = 500;
! 	char *bp, *cstart;
  
  	if (buf == NULL && (buf = malloc(bufsz)) == NULL)
  		FATAL("out of space for rex expr");
  	bp = buf;
! 	for ( ; ((c = input()) != '/' || openclass > 0) && c != 0; ) {
  		if (!adjbuf(&buf, &bufsz, bp-buf+3, 500, &bp, "regexpr"))
  			FATAL("out of space for reg expr %.10s...", buf);
  		if (c == '\n') {
***************
*** 541,550 ****
  			*bp++ = '\\';
  			*bp++ = input();
  		} else {
! 			if (c == '[')
! 				openclass = 1;
! 			else if (c == ']')
! 				openclass = 0;
  			*bp++ = c;
  		}
  	}
--- 541,565 ----
  			*bp++ = '\\';
  			*bp++ = input();
  		} else {
! 			/*
! 			 * POSIX requires a slash in a regexp to be escaped,
! 			 * other awks don't require it to be escaped inside
! 			 * a character class.
! 			 */
! 			if (!do_posix) {
! 				if (c == '[') {
! 					if (++openclass == 1)
! 						cstart = bp;
! 				} else if (c == ']' && openclass > 0) {
! 					/*
! 					 * A ']' as the first char in a
! 					 * class is treated literally.
! 					 */
! 					if (cstart != bp - 1 &&
! 					    (cstart != bp - 2 || bp[-1] != '^'))
! 						openclass--;
! 				}
! 			}
  			*bp++ = c;
  		}
  	}