commit 724fd07a67f135c74eba57e9f25fd342201ec722
Author: Peter Stephenson <pws@users.sourceforge.net>
Date:   Sat Dec 3 17:24:45 2011 +0000

    29934: Stef van Vlierberghe: uninitialised memory after lexer realloc

diff --git a/Src/lex.c b/Src/lex.c
index 90c4eff..05f54f8 100644
--- a/Src/lex.c
+++ b/Src/lex.c
@@ -567,22 +567,14 @@ add(int c)
 {
     *bptr++ = c;
     if (bsiz == ++len) {
-#if 0
-	int newbsiz;
-
-	newbsiz = bsiz * 8;
-	while (newbsiz < inbufct)
-	    newbsiz *= 2;
-	bptr = len + (tokstr = (char *)hrealloc(tokstr, bsiz, newbsiz));
-	bsiz = newbsiz;
-#endif
-
 	int newbsiz = bsiz * 2;
 
 	if (newbsiz > inbufct && inbufct > bsiz)
 	    newbsiz = inbufct;
 
 	bptr = len + (tokstr = (char *)hrealloc(tokstr, bsiz, newbsiz));
+	/* len == bsiz, so bptr is at the start of newly allocated memory */
+	memset(bptr, 0, newbsiz - bsiz);
 	bsiz = newbsiz;
     }
 }