Improve handling of the roff(7) "\t" escape sequence:

* Parsing macro arguments has to be done in copy mode,
  which implies replacing "\t" by a literal tab character.
* Otherwise, render "\t" as the empty string, not as a 't' character.

This fixes formatting of the distfile example in the oldrdist(1) manual.
This also shows up in the unzip(1) manual as one of several issues
preventing the removal of USE_GROFF from the archivers/unzip port.
Thanks to espie@ for attracting my attention to the unzip(1) manual.

5 files changed, 141 insertions, 2 deletions

diff --git a/regress/usr.bin/mandoc/char/space/Makefile b/regress/usr.bin/mandoc/char/space/Makefile
index 7ce50af3cb1..578488d78ac 100644
--- a/regress/usr.bin/mandoc/char/space/Makefile
+++ b/regress/usr.bin/mandoc/char/space/Makefile
@@ -1,6 +1,6 @@
-# $OpenBSD: Makefile,v 1.6 2012/07/16 21:14:05 schwarze Exp $
+# $OpenBSD: Makefile,v 1.7 2013/06/20 22:29:38 schwarze Exp $
 
 REGRESS_TARGETS  = leading-mdoc leading-man multiple zerowidth
-REGRESS_TARGETS += eos nobreak tab tab-man
+REGRESS_TARGETS += eos nobreak tab tab-man esct-mdoc esct-man
 
 .include <bsd.regress.mk>
diff --git a/regress/usr.bin/mandoc/char/space/esct-man.in b/regress/usr.bin/mandoc/char/space/esct-man.in
new file mode 100644
index 00000000000..90aed2c7477
--- /dev/null
+++ b/regress/usr.bin/mandoc/char/space/esct-man.in
@@ -0,0 +1,34 @@
+.TH SPACE-ESCT-MAN 1 2013-06-20 OpenBSD
+.SH NAME
+SPACE-T-MAN \- the t escape sequence in pages with man macros
+.SH DESCRIPTION
+In plain text:
+.br
+single	tab
+.br
+single\tescape-t
+.br
+double		tab
+.br
+double\t\tescape-t
+.br
+\tThis line starts with escape-t and comes close to the right margin.
+\tThe next line starts with escape-t as well.
+.sp
+In a literal display:
+.nf
+single	tab
+single\tescape-t
+double		tab
+double\t\tescape-t
+.fi
+.sp
+After the IP macro:
+.IP single	tab 3n
+text
+.IP single\tescape-t 3n
+text
+.PP
+After font macros:
+.br
+.B single\ttab
diff --git a/regress/usr.bin/mandoc/char/space/esct-man.out_ascii b/regress/usr.bin/mandoc/char/space/esct-man.out_ascii
new file mode 100644
index 00000000000..017b3b133d3
--- /dev/null
+++ b/regress/usr.bin/mandoc/char/space/esct-man.out_ascii
@@ -0,0 +1,36 @@
+SPACE-ESCT-MAN(1)          OpenBSD Reference Manual          SPACE-ESCT-MAN(1)
+
+
+
+NNAAMMEE
+       SPACE-T-MAN - the t escape sequence in pages with man macros
+
+DDEESSCCRRIIPPTTIIOONN
+       In plain text:
+       single    tab
+       singleescape-t
+       double         tab
+       doubleescape-t
+       This line starts with escape-t and comes close to the right margin.
+       The next line starts with escape-t as well.
+
+       In a literal display:
+       single    tab
+       singleescape-t
+       double         tab
+       doubleescape-t
+
+       After the IP macro:
+
+       single    tab
+          text
+
+       single    escape-t
+          text
+
+       After font macros:
+       ssiinnggllee    ttaabb
+
+
+
+OpenBSD                           2013-06-20                 SPACE-ESCT-MAN(1)
diff --git a/regress/usr.bin/mandoc/char/space/esct-mdoc.in b/regress/usr.bin/mandoc/char/space/esct-mdoc.in
new file mode 100644
index 00000000000..6aa8c3923bc
--- /dev/null
+++ b/regress/usr.bin/mandoc/char/space/esct-mdoc.in
@@ -0,0 +1,35 @@
+.Dd $Mdocdate: June 20 2013 $
+.Dt SPACE-ESCT-MDOC 1
+.Os OpenBSD
+.Sh NAME
+.Nm space-esct-mdoc
+.Nd the t escape sequence in pages with mdoc macros
+.Sh DESCRIPTION
+In plain text:
+.Pp
+single	tab
+.Pp
+single\tescape-t
+.Pp
+double		tab
+.Pp
+double\t\tescape-t
+.Pp
+\tThis line starts with escape-t and comes close to the right margin.
+\tThe next line starts with escape-t as well.
+.Pp
+In an unfilled display:
+.Bd -unfilled -offset 3n
+single	tab
+single\tescape-t
+double		tab
+double\t\tescape-t
+.Ed
+.Pp
+In a literal display:
+.Bd -literal -offset 3n
+single	tab
+single\tescape-t
+double		tab
+double\t\tescape-t
+.Ed
diff --git a/regress/usr.bin/mandoc/char/space/esct-mdoc.out_ascii b/regress/usr.bin/mandoc/char/space/esct-mdoc.out_ascii
new file mode 100644
index 00000000000..b448b2a0e19
--- /dev/null
+++ b/regress/usr.bin/mandoc/char/space/esct-mdoc.out_ascii
@@ -0,0 +1,34 @@
+SPACE-ESCT-MDOC(1)         OpenBSD Reference Manual         SPACE-ESCT-MDOC(1)
+
+NNAAMMEE
+     ssppaaccee--eesscctt--mmddoocc - the t escape sequence in pages with mdoc macros
+
+DDEESSCCRRIIPPTTIIOONN
+     In plain text:
+
+     single    tab
+
+     singleescape-t
+
+     double         tab
+
+     doubleescape-t
+
+     This line starts with escape-t and comes close to the right margin.  The
+     next line starts with escape-t as well.
+
+     In an unfilled display:
+
+        single    tab
+        singleescape-t
+        double         tab
+        doubleescape-t
+
+     In a literal display:
+
+        single  tab
+        singleescape-t
+        double          tab
+        doubleescape-t
+
+OpenBSD                          June 20, 2013                         OpenBSD