Do not access a NULL pointer if a table contains a horizontal line

next to a table line having fewer columns than the table as a whole.
Bug found by Stephen Gregoratto <dev at sgregoratto dot me>
with aerc-config(5).

3 files changed, 99 insertions, 2 deletions

diff --git a/regress/tbl/layout/Makefile b/regress/tbl/layout/Makefile
index 9cc65754..a56cbc2f 100644
--- a/regress/tbl/layout/Makefile
+++ b/regress/tbl/layout/Makefile
@@ -1,7 +1,7 @@
-# $OpenBSD: Makefile,v 1.2 2015/01/30 00:27:09 schwarze Exp $
+# $OpenBSD: Makefile,v 1.4 2019/06/11 15:40:41 schwarze Exp $
 
 REGRESS_TARGETS	 = center complex empty emptyline
-REGRESS_TARGETS	+= lines lines-nogroff numbers span
+REGRESS_TARGETS	+= lines lines-nogroff numbers shortlines span
 LINT_TARGETS	 = complex empty
 
 # groff-1.22.3 defects:
diff --git a/regress/tbl/layout/shortlines.in b/regress/tbl/layout/shortlines.in
new file mode 100644
index 00000000..f6434619
--- /dev/null
+++ b/regress/tbl/layout/shortlines.in
@@ -0,0 +1,49 @@
+.\" $OpenBSD: shortlines.in,v 1.1 2019/06/11 15:40:41 schwarze Exp $
+.TH TBL-LAYOUT-SHORTLINES 1 "June 11, 2019"
+.SH NAME
+tbl-layout-shortlines \- table lines of different length
+.SH DESCRIPTION
+normal text
+.TS
+allbox tab(:);
+L L
+L
+L L.
+left:right
+short
+left:right
+.TE
+.sp
+.TS
+allbox tab(:);
+L L
+L
+L
+L L.
+left:right
+first short
+second short
+left:right
+.TE
+.sp
+.TS
+allbox tab(:);
+L L L
+L L
+L.
+left:middle:right
+short:line
+very short
+.TE
+.sp
+.TS
+allbox tab(:);
+L
+L L
+L L L.
+very short
+short:line
+left:middle:right
+.TE
+
+
diff --git a/regress/tbl/layout/shortlines.out_ascii b/regress/tbl/layout/shortlines.out_ascii
new file mode 100644
index 00000000..02fe01d7
--- /dev/null
+++ b/regress/tbl/layout/shortlines.out_ascii
@@ -0,0 +1,48 @@
+TBL-LAYOUT-SHORTLINES(1)    General Commands Manual   TBL-LAYOUT-SHORTLINES(1)
+
+
+
+NNAAMMEE
+       tbl-layout-shortlines - table lines of different length
+
+DDEESSCCRRIIPPTTIIOONN
+       normal text
+
+       +------+-------+
+       |left  | right |
+       +------+-------+
+       |short |       |
+       +------+-------+
+       |left  | right |
+       +------+-------+
+
+       +-------------+-------+
+       |left         | right |
+       +-------------+-------+
+       |first short  |       |
+       +-------------+-------+
+       |second short |       |
+       +-------------+-------+
+       |left         | right |
+       +-------------+-------+
+
+       +-----------+--------+-------+
+       |left       | middle | right |
+       +-----------+--------+-------+
+       |short      | line   |       |
+       +-----------+--------+-------+
+       |very short |        |       |
+       +-----------+--------+-------+
+
+       +-----------+--------+-------+
+       |very short |        |       |
+       +-----------+--------+-------+
+       |short      | line   |       |
+       +-----------+--------+-------+
+       |left       | middle | right |
+       +-----------+--------+-------+
+
+
+
+
+OpenBSD                          June 11, 2019        TBL-LAYOUT-SHORTLINES(1)