man: Allow disabling warnings enabled by default in groff

5 files changed, 27 insertions, 17 deletions

diff --git a/NEWS.md b/NEWS.md
index d4ef874d..3f03f4ba 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -30,6 +30,8 @@ Improvements:
    options on to `whatis` and `apropos` respectively.
  * Always pass a line length to `nroff`, even if we believe that it matches
    the default.
+ * Allow disabling `groff` warnings via `man --warnings`, by prefixing a
+   warning name with `!`.
 
 man-db 2.11.2 (8 January 2023)
 ==============================
diff --git a/man/Rules.man b/man/Rules.man
index 55ff35d6..5d273256 100644
--- a/man/Rules.man
+++ b/man/Rules.man
@@ -25,8 +25,7 @@ CLEANFILES = $(man1_MANS) $(man5_MANS) $(man8_MANS) replace.sed
 
 if !CROSS_COMPILING
 TESTS_ENVIRONMENT = top_builddir="$(top_builddir)"; export top_builddir; \
-		    LINGUA="$(LINGUA)"; export LINGUA; \
-		    EGREP="$(EGREP)"; export EGREP;
+		    LINGUA="$(LINGUA)"; export LINGUA;
 LOG_COMPILER = @SHELL@ $(top_srcdir)/man/check-man
 TESTS = $(man1_MANS) $(man5_MANS) $(man8_MANS)
 endif
diff --git a/man/check-man b/man/check-man
index f8985a0d..b28e039c 100755
--- a/man/check-man
+++ b/man/check-man
@@ -2,8 +2,8 @@
 set -e
 
 # Check that a manual page formats without errors. Lintian does something
-# similar for Debian packages. Relies on top_builddir, LINGUA, and EGREP
-# variables exported from 'make check', or you can set them manually.
+# similar for Debian packages. Relies on top_builddir and LINGUA variables
+# exported from 'make check', or you can set them manually.
 
 if [ -z "$top_builddir" ]; then
 	echo "top_builddir unset; try 'make check' instead?"
@@ -11,28 +11,27 @@ if [ -z "$top_builddir" ]; then
 elif [ -z "$LINGUA" ]; then
 	echo "LINGUA unset; try 'make check' instead?"
 	exit 77
-elif [ -z "$EGREP" ]; then
-	echo "EGREP unset; try 'make check' instead?"
-	exit 77
 fi
 
 [ -x "$top_builddir/src/man" ] || exit 77
 
+warnings=mac
+# Ignore wrapping failures for CJK manual pages; this should go away once
+# groff supports these natively.
+# Indeed, even for other languages we're going to get "cannot adjust line"
+# if %manpath_config_file% expands to something long. Hmm. We'll just ignore
+# this across the board for now.
+warnings="$warnings,!break"
+
 code=0
 errors="$(LC_ALL=C MANWIDTH=80 MAN_KEEP_FORMATTING=1 "$top_builddir/libtool" \
 		--mode=execute \
 		-dlopen "$top_builddir/lib/.libs/libman.la" \
 		-dlopen "$top_builddir/libdb/.libs/libmandb.la" \
-		"$top_builddir/src/man" --warnings -E UTF-8 -l "$1" \
+		"$top_builddir/src/man" --warnings="$warnings" -E UTF-8 \
+		-l "$1" \
 		2>&1 >/dev/null)" || code=$?
 
-# Ignore wrapping failures for CJK manual pages; this should go away once
-# groff supports these natively.
-# Indeed, even for other languages we're going to get "cannot adjust line"
-# if %manpath_config_file% expands to something long. Hmm. We'll just ignore
-# this across the board for now.
-errors="$(echo "$errors" | $EGREP -v "(cannot adjust line|(can't|cannot) break line)")" || true
-
 if [ "$code" != 0 ]; then
 	echo "man -E UTF-8 -l $1 failed with exit status $code and error output:"
 	echo "$errors"
diff --git a/man/man1/man.man1 b/man/man1/man.man1
index cf27f0fb..6319ab9f 100644
--- a/man/man1/man.man1
+++ b/man/man1/man.man1
@@ -436,6 +436,12 @@ pages.
 .I warnings
 is a comma-separated list of warning names; if it is not supplied, the
 default is "mac".
+To disable a
+.I groff
+warning, prefix it with "!": for example,
+.B \-\-warnings=mac,!break
+enables warnings in the "mac" category and disables warnings in the "break"
+category.
 See the \(lqWarnings\(rq node in
 .B info groff
 for a list of available warning names.
diff --git a/src/man.c b/src/man.c
index 68515eed..5d3be39f 100644
--- a/src/man.c
+++ b/src/man.c
@@ -1429,8 +1429,12 @@ static pipeline *make_roff_command (const char *dir, const char *file,
 #endif /* !TROFF_IS_GROFF */
 
 #ifdef NROFF_WARNINGS
-		GL_LIST_FOREACH (roff_warnings, warning)
-			pipecmd_argf (cmd, "-w%s", warning);
+		GL_LIST_FOREACH (roff_warnings, warning) {
+			if (warning[0] == '!')
+				pipecmd_argf (cmd, "-W%s", warning + 1);
+			else
+				pipecmd_argf (cmd, "-w%s", warning);
+		}
 #endif /* NROFF_WARNINGS */
 
 #ifdef HEIRLOOM_NROFF