build: Make update-authors convenience target runnable from Meson

Signed-off-by: Simon McVittie <smcv@collabora.com>

Makefile.am

@@ -40,7 +40,7 @@ EXTRA_DIST =			\
 all-local: Doxyfile
 
 update-authors:
-	( cd $(srcdir) && git shortlog -s -e ) | cut -c 8- | sort > $(srcdir)/AUTHORS
+	cd $(srcdir) && ./maint/update-authors.sh
 
 DISTCHECK_CONFIGURE_FLAGS = \
 	--enable-xml-docs \

maint/update-authors.sh

@@ -0,0 +1,11 @@
+# Copyright 2010 Lennart Poettering
+# Copyright 2022 Simon McVittie
+# SPDX-License-Identifier: MIT
+
+set -eux
+
+if [ -n "${MESON_SOURCE_ROOT-}" ]; then
+    cd "${MESON_SOURCE_ROOT}"
+fi
+
+git shortlog -s -e | cut -c 8- | sort > AUTHORS

meson.build

@@ -950,6 +950,13 @@ bonus_files = files(
     'README',
 )
 
+if platform_unix
+    run_target(
+        'maintainer-update-authors',
+        command: 'maint/update-authors.sh',
+    )
+endif
+
 subdir('dbus')
 subdir('bus')
 subdir('tools')