Multiple parser and formatter fixes for line drawing in tbl(7).

* Allow mixing vertical line bars with the layout options
of the preceding layout cell.
* Correctly combine box options with layout lines.
* Correctly print vertical lines in data rows, with the right spacing.
* Correctly print cross markers and left and right ends of
horizontal lines even if vertical lines differ above and below.
* Avoid the bogus error message "no table data cells"
when a table data section starts with a horizontal line.
No increase in code size.

2 files changed, 26 insertions, 1 deletions

diff --git a/regress/usr.bin/mandoc/tbl/layout.in b/regress/usr.bin/mandoc/tbl/layout.in
index 3e505bc34d6..648018320ff 100644
--- a/regress/usr.bin/mandoc/tbl/layout.in
+++ b/regress/usr.bin/mandoc/tbl/layout.in
@@ -5,7 +5,7 @@ tbl-layout \- table layout
 normal text
 .TS
 box tab(:);
-lp-1|l bsil|||l,l|l	ilb^i|||l.
+l|p-1l bsil|||l,l|l	ilb^|i||l.
 a:b:c:d
 e:f:g:h:i
 .TE
@@ -20,3 +20,18 @@ c:d
 .TE
 .PP
 normal text
+.TS
+tab(:);
+||l||l||
+|l|l|
+ll.
+_
+a:b
+_
+c:d
+_
+e:f
+_
+.TE
+.PP
+normal text
diff --git a/regress/usr.bin/mandoc/tbl/layout.out_ascii b/regress/usr.bin/mandoc/tbl/layout.out_ascii
index 8aaaf49a894..bbf360437ef 100644
--- a/regress/usr.bin/mandoc/tbl/layout.out_ascii
+++ b/regress/usr.bin/mandoc/tbl/layout.out_ascii
@@ -20,6 +20,16 @@ DDEESSCCRRIIPPTTIIOONN
        +------+
        normal text
 
+       +--++--+
+       |a ||b |
+       +--++--+
+       |c | d |
+       +--+---+
+        e   f
+       --------
+
+       normal text
+
 
 
 OpenBSD                        January 26, 2015                  TBL-LAYOUT(1)