===================================================================
RCS file: /cvs/mandoc/roff.c,v
retrieving revision 1.352
retrieving revision 1.353
diff -u -p -r1.352 -r1.353
--- mandoc/roff.c	2018/12/15 19:30:26	1.352
+++ mandoc/roff.c	2018/12/18 22:00:02	1.353
@@ -1,4 +1,4 @@
-/*	$Id: roff.c,v 1.352 2018/12/15 19:30:26 schwarze Exp $ */
+/*	$Id: roff.c,v 1.353 2018/12/18 22:00:02 schwarze Exp $ */
 /*
  * Copyright (c) 2008-2012, 2014 Kristaps Dzonsons <kristaps@bsd.lv>
  * Copyright (c) 2010-2015, 2017, 2018 Ingo Schwarze <schwarze@openbsd.org>
@@ -1545,6 +1545,103 @@ roff_res(struct roff *r, struct buf *buf, int ln, int 
 	}
 	return ROFF_CONT;
 }
+
+/*
+ * Parse a quoted or unquoted roff-style request or macro argument.
+ * Return a pointer to the parsed argument, which is either the original
+ * pointer or advanced by one byte in case the argument is quoted.
+ * NUL-terminate the argument in place.
+ * Collapse pairs of quotes inside quoted arguments.
+ * Advance the argument pointer to the next argument,
+ * or to the NUL byte terminating the argument line.
+ */
+char *
+mandoc_getarg(char **cpp, int ln, int *pos)
+{
+	char	 *start, *cp;
+	int	  quoted, pairs, white;
+
+	/* Quoting can only start with a new word. */
+	start = *cpp;
+	quoted = 0;
+	if ('"' == *start) {
+		quoted = 1;
+		start++;
+	}
+
+	pairs = 0;
+	white = 0;
+	for (cp = start; '\0' != *cp; cp++) {
+
+		/*
+		 * Move the following text left
+		 * after quoted quotes and after "\\" and "\t".
+		 */
+		if (pairs)
+			cp[-pairs] = cp[0];
+
+		if ('\\' == cp[0]) {
+			/*
+			 * In copy mode, translate double to single
+			 * backslashes and backslash-t to literal tabs.
+			 */
+			switch (cp[1]) {
+			case 'a':
+			case 't':
+				cp[0] = '\t';
+				/* FALLTHROUGH */
+			case '\\':
+				pairs++;
+				cp++;
+				break;
+			case ' ':
+				/* Skip escaped blanks. */
+				if (0 == quoted)
+					cp++;
+				break;
+			default:
+				break;
+			}
+		} else if (0 == quoted) {
+			if (' ' == cp[0]) {
+				/* Unescaped blanks end unquoted args. */
+				white = 1;
+				break;
+			}
+		} else if ('"' == cp[0]) {
+			if ('"' == cp[1]) {
+				/* Quoted quotes collapse. */
+				pairs++;
+				cp++;
+			} else {
+				/* Unquoted quotes end quoted args. */
+				quoted = 2;
+				break;
+			}
+		}
+	}
+
+	/* Quoted argument without a closing quote. */
+	if (1 == quoted)
+		mandoc_msg(MANDOCERR_ARG_QUOTE, ln, *pos, NULL);
+
+	/* NUL-terminate this argument and move to the next one. */
+	if (pairs)
+		cp[-pairs] = '\0';
+	if ('\0' != *cp) {
+		*cp++ = '\0';
+		while (' ' == *cp)
+			cp++;
+	}
+	*pos += (int)(cp - start) + (quoted ? 1 : 0);
+	*cpp = cp;
+
+	if ('\0' == *cp && (white || ' ' == cp[-1]))
+		mandoc_msg(MANDOCERR_SPACE_EOL, ln, *pos, NULL);
+
+	return start;
+}
+
 
 /*
  * Process text streams.