From: Emden R. Gansner <erg@research.att.com>
Date: Mon, 17 Jun 2013 21:41:10 +0000 (-0400)
Subject: Fix bug 2296: logic was incorrect in do{}while loop.
X-Git-Tag: LAST_LIBGRAPH~32^2~187
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=e3d663e77a9a2f1aae6ed1031ddf7a59bae3c85b;p=graphviz

Fix bug 2296: logic was incorrect in do{}while loop.
---

diff --git a/lib/cgraph/io.c b/lib/cgraph/io.c
index d6033a08c..c677c4f6b 100644
--- a/lib/cgraph/io.c
+++ b/lib/cgraph/io.c
@@ -112,10 +112,16 @@ memiofread(void *chan, char *buf, int bufsize)
     l = 0;
     ptr = s->data + s->cur;
     optr = buf;
+    /* We know we have at least one character */
+    c = *ptr++;
     do {
-        *optr++ = c = *ptr++;
+        *optr++ = c;
         l++;
-    } while (c && (c != '\n') && (l < bufsize));
+	/* continue if c is not newline, we have space in buffer,
+	 * and next character is non-null (we are working with
+	 * null-terminated strings.
+	 */
+    } while ((c != '\n') && (l < bufsize) && (c = *ptr++));
     s->cur += l;
     return l;
 }