Rename mandoc_getarg() to roff_getarg() and pass it the roff parser

struct as an argument such that after copy-in, it can call roff_expand()
once again, which used to be called roff_res() before this.  This
fixes a subtle low-level roff(7) parsing bug reported by Fabio
Scotoni <fabio at esse dot ch> in the 4.4BSD-Lite2 mdoc.samples(7)
manual page, because that page used an escaped escape sequence in
a macro argument.

To expand escaped escape sequences in quoted mdoc(7) arguments, too,
stop bypassing the call to roff_getarg() in mdoc_argv.c, function args()
for this case.  This does not solve the case of escaped escape sequences
in quoted .Bl -column phrases yet.

Because roff_expand() can make the string longer, roff_getarg() can no
longer operate in-place but needs to malloc(3) the returned string.
In the high-level parsers, free(3) that string after processing it.

1 files changed, 2 insertions, 1 deletions

diff --git a/usr.bin/mandoc/libmdoc.h b/usr.bin/mandoc/libmdoc.h
index f9639a992fd..6eab77501d4 100644
--- a/usr.bin/mandoc/libmdoc.h
+++ b/usr.bin/mandoc/libmdoc.h
@@ -1,4 +1,4 @@
-/*	$OpenBSD: libmdoc.h,v 1.85 2018/12/04 02:53:45 schwarze Exp $ */
+/*	$OpenBSD: libmdoc.h,v 1.86 2018/12/21 16:58:49 schwarze Exp $ */
 /*
  * Copyright (c) 2008, 2009, 2010, 2011 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2013,2014,2015,2017,2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -38,6 +38,7 @@ enum	margserr {
 	ARGS_ERROR,
 	ARGS_EOLN, /* end-of-line */
 	ARGS_WORD, /* normal word */
+	ARGS_ALLOC, /* normal word from roff_getarg() */
 	ARGS_PUNCT, /* series of punctuation */
 	ARGS_PHRASE /* Bl -column phrase */
 };