do not crash when a tbl(7) cell uses roman font

[mandoc.git] / term_ascii.c

diff --git a/term_ascii.c b/term_ascii.c
index 368623cac1057b9e33e759c5810f17bd29acc787..bf7e9b639e04e39385196b28a40145b87fabf041 100644 (file)
--- a/term_ascii.c
+++ b/term_ascii.c
@@ -1,7 +1,7 @@
-/*     $Id: term_ascii.c,v 1.64 2018/11/28 14:23:06 schwarze Exp $ */
+/* $Id: term_ascii.c,v 1.66 2020/09/09 13:45:05 schwarze Exp $ */
 /*
  * Copyright (c) 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
- * Copyright (c) 2014, 2015, 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
+ * Copyright (c) 2014,2015,2017,2018,2020 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
@@ -232,7 +232,10 @@ ascii_endline(struct termp *p)
 {
 
        p->line++;
-       p->tcol->offset -= p->ti;
+       if ((int)p->tcol->offset > p->ti)
+               p->tcol->offset -= p->ti;
+       else
+               p->tcol->offset = 0;
        p->ti = 0;
        putchar('\n');
 }
@@ -242,7 +245,14 @@ ascii_advance(struct termp *p, size_t len)
 {
        size_t          i;
 
-       assert(len < UINT16_MAX);
+       /*
+        * XXX We used to have "assert(len < UINT16_MAX)" here.
+        * that is not quite right because the input document
+        * can trigger that by merely providing large input.
+        * For now, simply truncate.
+        */
+       if (len > 256)
+               len = 256;
        for (i = 0; i < len; i++)
                putchar(' ');
 }
@@ -380,7 +390,14 @@ locale_advance(struct termp *p, size_t len)
 {
        size_t          i;
 
-       assert(len < UINT16_MAX);
+       /*
+        * XXX We used to have "assert(len < UINT16_MAX)" here.
+        * that is not quite right because the input document
+        * can trigger that by merely providing large input.
+        * For now, simply truncate.
+        */
+       if (len > 256)
+               len = 256;
        for (i = 0; i < len; i++)
                putwchar(L' ');
 }
@@ -390,7 +407,10 @@ locale_endline(struct termp *p)
 {
 
        p->line++;
-       p->tcol->offset -= p->ti;
+       if ((int)p->tcol->offset > p->ti)
+               p->tcol->offset -= p->ti;
+       else 
+               p->tcol->offset = 0;
        p->ti = 0;
        putwchar(L'\n');
 }