Initialize the local variable "lastln" in mparse_buf_r().

While there is no bug, it logically makes sense given the meaning
of the variable that lastln is NULL as long as firstln is NULL.

Michal Nowak <mnowak at startmail dot com> reported that gcc 4.4.4
and 7.4.0 on illumos throw -Wuninitialized false positives.

1 files changed, 2 insertions, 2 deletions

diff --git a/read.c b/read.c
index b9d67854..6c27a47a 100644
--- a/read.c
+++ b/read.c
@@ -1,4 +1,4 @@
-/*	$Id: read.c,v 1.212 2019/03/19 16:26:08 schwarze Exp $ */
+/*	$Id: read.c,v 1.213 2019/06/03 19:58:02 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2019 Ingo Schwarze <schwarze@openbsd.org>
@@ -157,7 +157,7 @@ mparse_buf_r(struct mparse *curp, struct buf blk, size_t i, int start)
 	ln.sz = 256;
 	ln.buf = mandoc_malloc(ln.sz);
 	ln.next = NULL;
-	firstln = loop = NULL;
+	firstln = lastln = loop = NULL;
 	lnn = curp->line;
 	pos = 0;
 	inloop = 0;