When looking for column separators on tbl(7) data lines, properly skip

escape sequences; do not misinterpret bytes from the middle of escape
sequence names or arguments as column separators.
Bug reported and patch tested by Oliver dot Corff at email dot de.

diff --git a/usr.bin/mandoc/tbl_data.c b/usr.bin/mandoc/tbl_data.c
index 11b0a91..93039de 100644 (file)
--- a/usr.bin/mandoc/tbl_data.c
+++ b/usr.bin/mandoc/tbl_data.c
@@ -1,7 +1,7 @@
-/*     $OpenBSD: tbl_data.c,v 1.41 2021/05/15 17:16:38 schwarze Exp $ */
+/*     $OpenBSD: tbl_data.c,v 1.42 2021/05/18 13:22:37 schwarze Exp $ */
 /*
  * Copyright (c) 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2011,2015,2017,2018,2019 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2011,2015,2017-2019,2021 Ingo Schwarze <schwarze@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -44,6 +44,7 @@ getdata(struct tbl_node *tbl, struct tbl_span *dp,
        struct tbl_dat  *dat, *pdat;
        struct tbl_cell *cp;
        struct tbl_span *pdp;
+       const char      *ccp;
        int              sv;
 
        /*
@@ -52,8 +53,11 @@ getdata(struct tbl_node *tbl, struct tbl_span *dp,
         */
 
        sv = *pos;
-       while (p[*pos] != '\0' && p[*pos] != tbl->opts.tab)
-               (*pos)++;
+       ccp = p + sv;
+       while (*ccp != '\0' && *ccp != tbl->opts.tab)
+               if (*ccp++ == '\\')
+                       mandoc_escape(&ccp, NULL, NULL);
+       *pos = ccp - p;
 
        /* Advance to the next layout cell, skipping spanners. */