From: Ben Pfaff <blp@cs.stanford.edu>
Date: Fri, 19 Apr 2024 16:46:05 +0000 (-0700)
Subject: ascii: Avoid assertion failure on width underflow in text_draw().
X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9063f003ce7da10c53ec96bae81af42c2dc765d7;p=pspp

ascii: Avoid assertion failure on width underflow in text_draw().

Thanks to Zhou Geng for reporting this bug as poc33 in the report here:
https://lists.gnu.org/archive/html/bug-gnu-pspp/2024-03/msg00015.html
---

diff --git a/src/output/ascii.c b/src/output/ascii.c
index d581675fe3..2676792b8d 100644
--- a/src/output/ascii.c
+++ b/src/output/ascii.c
@@ -827,6 +827,11 @@ text_draw (struct ascii_driver *a, enum table_halign halign, bool numeric,
           width -= w;
         }
     }
+  if (width >= SIZE_MAX / 2)
+    {
+      /* Width underflow. */
+      return;
+    }
   if (n == 0)
     return;