From: Matthew Fernandez <matthew.fernandez@gmail.com>
Date: Fri, 23 Dec 2022 03:04:58 +0000 (-0800)
Subject: common scanEntity: use a more appropriate type for 'len'
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3a2456e7d3d7e4ac2a79f84bc61702d029687a52;p=graphviz

common scanEntity: use a more appropriate type for 'len'

This addresses a problem where the subtraction of two pointers, `endp - t`, can
in theory exceed the size of an `int`. In practice this cannot occur, but using
a more correct type squashes a -Wconversion and -Wsign-conversion warning in
this code.
---

diff --git a/lib/common/utils.c b/lib/common/utils.c
index 5e79b6a49..d0aed9a76 100644
--- a/lib/common/utils.c
+++ b/lib/common/utils.c
@@ -1257,12 +1257,12 @@ char* scanEntity (char* t, agxbuf* xb)
 {
     char*  endp = strchr (t, ';');
     struct entities_s key, *res;
-    int    len;
+    size_t len;
     char   buf[MAXENTLEN+1];
 
     agxbputc(xb, '&');
     if (!endp) return t;
-    if (((len = endp-t) > MAXENTLEN) || (len < 2)) return t;
+    if (((len = (size_t)(endp - t)) > MAXENTLEN) || (len < 2)) return t;
     strncpy (buf, t, len);
     buf[len] = '\0';
     key.name =  buf;