The syntax of the roff(7) .mc request is quite special

and the roff_onearg() parsing function is too generic,
so provide a dedicated parsing function instead.

This fixes an assertion failure when an \o escape sequence is
passed as the argument; the bug was found by tb@ using afl(1).
It also makes mandoc output more similar to groff in various cases.

4 files changed, 63 insertions, 0 deletions

diff --git a/regress/roff/mc/Makefile b/regress/roff/mc/Makefile
new file mode 100644
index 00000000..445af7d3
--- /dev/null
+++ b/regress/roff/mc/Makefile
@@ -0,0 +1,6 @@
+# $OpenBSD: Makefile,v 1.1 2022/04/28 16:16:46 schwarze Exp $
+
+REGRESS_TARGETS	 = args
+LINT_TARGETS	 = args
+
+.include <bsd.regress.mk>
diff --git a/regress/roff/mc/args.in b/regress/roff/mc/args.in
new file mode 100644
index 00000000..4e9b245f
--- /dev/null
+++ b/regress/roff/mc/args.in
@@ -0,0 +1,29 @@
+.\" $OpenBSD: args.in,v 1.1 2022/04/28 16:16:46 schwarze Exp $
+.TH MC-ARGS 1 "April 28, 2022"
+.SH NAME
+mc-args \- arguments to the .mc request
+.SH DESCRIPTION
+.ll 50n
+.nf
+initial text
+.mc |suffix
+ASCII character in the margin
+.mc \CXX
+invalid escape sequence
+.mc \!
+unsupported escape sequence
+.mc \a
+ignored escape sequence
+.mc \(ba
+special character in the margin
+.mc \[integral]
+special character represented as string
+.mc \fR
+font escape in the margin
+.mc \N'124'
+numbered character in the margin
+.mc \[u007C]suffix
+Unicode character in the margin
+.mc \o'o/'
+overstriking in the margin
+.ll
diff --git a/regress/roff/mc/args.out_ascii b/regress/roff/mc/args.out_ascii
new file mode 100644
index 00000000..d1a56be6
--- /dev/null
+++ b/regress/roff/mc/args.out_ascii
@@ -0,0 +1,19 @@
+MC-ARGS(1)                  General Commands Manual                 MC-ARGS(1)
+
+NNAAMMEE
+       mc-args - arguments to the .mc request
+
+DDEESSCCRRIIPPTTIIOONN
+       initial text
+       ASCII character in the margin               |
+       invalid escape sequence
+       unsupported escape sequence
+       ignored escape sequence
+       special character in the margin             |
+       special character represented as string     <integral>
+       font escape in the margin
+       numbered character in the margin            |
+       Unicode character in the margin             |
+       overstriking in the margin
+
+OpenBSD                         April 28, 2022                      MC-ARGS(1)
diff --git a/regress/roff/mc/args.out_lint b/regress/roff/mc/args.out_lint
new file mode 100644
index 00000000..56ed4e28
--- /dev/null
+++ b/regress/roff/mc/args.out_lint
@@ -0,0 +1,9 @@
+mandoc: args.in:9:6: WARNING: ignoring distance argument: mc ... suffix
+mandoc: args.in:11:5: WARNING: invalid escape sequence: \C
+mandoc: args.in:11:5: ERROR: skipping unusable escape sequence: mc \C
+mandoc: args.in:13:5: UNSUPP: unsupported escape sequence: \!
+mandoc: args.in:13:5: ERROR: skipping unusable escape sequence: mc \!
+mandoc: args.in:15:5: ERROR: skipping unusable escape sequence: mc \a
+mandoc: args.in:21:5: ERROR: skipping unusable escape sequence: mc \fR
+mandoc: args.in:25:13: WARNING: ignoring distance argument: mc ... suffix
+mandoc: args.in:27:5: ERROR: skipping unusable escape sequence: mc \o'o/'