[atkmm] Subprojects can use meson.add_dist_script() if meson.version() >= 0.58.0

[Kjell Ahlstedt <kjellahl src gnome org>]

commit e4ee05bdacc2d92edfb4632efbf4c8f13dbdfee2
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Wed May 5 16:50:53 2021 +0200

    Subprojects can use meson.add_dist_script() if meson.version() >= 0.58.0
    
    Call add_dist_script() in a subproject, if meson.version() >= 0.58.0.

 atk/atkmm/meson.build     |  5 ++---
 doc/reference/meson.build |  5 ++---
 meson.build               | 11 +++++++----
 3 files changed, 11 insertions(+), 10 deletions(-)
---
diff --git a/atk/atkmm/meson.build b/atk/atkmm/meson.build
index e9e4ca9..2eb4430 100644
--- a/atk/atkmm/meson.build
+++ b/atk/atkmm/meson.build
@@ -3,7 +3,7 @@
 # Input: atkmm_build_dep, atkmm_pcname, maintainer_mode, project_source_root,
 #        generate_binding_py, m4_files, atkmm_libversion, install_includedir,
 #        python3, atkmm_rc, dummy_header_py, gmmproc_dir, msvc14x_toolset_ver,
-#        macos_darwin_versions
+#        macos_darwin_versions, can_add_dist_script
 # Output: hg_ccg_basenames, extra_h_files, built_h_file_targets, built_files_root,
 #         atkmm_own_dep
 
@@ -216,9 +216,8 @@ meson.add_install_script(
   hg_ccg_basenames
 )
 
-if not meson.is_subproject()
+if can_add_dist_script
   # Distribute built files.
-  # (add_dist_script() is not allowed in a subproject)
   meson.add_dist_script(
     python3.path(), generate_binding_py, 'dist_built_files',
     built_h_cc_dir,
diff --git a/doc/reference/meson.build b/doc/reference/meson.build
index 95ea53c..611cb87 100644
--- a/doc/reference/meson.build
+++ b/doc/reference/meson.build
@@ -2,7 +2,7 @@
 
 # Input: built_files_root, project_source_root, atkmm_pcname, hg_ccg_basenames,
 #        extra_h_files, built_h_file_targets, install_datadir, python3,
-#        doc_reference_py
+#        doc_reference_py, can_add_dist_script
 # Output: install_docdir, install_devhelpdir, tag_file
 
 tag_file_modules = [
@@ -136,9 +136,8 @@ meson.add_install_script(
   docinstall_flags
 )
 
-if not meson.is_subproject()
+if can_add_dist_script
   # Distribute built files and files copied by mm-common-get.
-  # (add_dist_script() is not allowed in a subproject)
   meson.add_dist_script(
     python3.path(), doc_reference_py, 'dist_doc',
     doctool_dir,
diff --git a/meson.build b/meson.build
index 82452aa..c720b4e 100644
--- a/meson.build
+++ b/meson.build
@@ -212,15 +212,17 @@ if is_msvc
   endforeach
 endif
 
+# add_dist_script() is not allowed in a subproject if meson.version() < 0.58.0.
+can_add_dist_script = not meson.is_subproject() or meson.version().version_compare('>= 0.58.0')
+
 subdir('codegen/extradefs')
 subdir('atk')
 subdir('MSVC_NMake/atkmm')
 subdir('atk/atkmm')
 subdir('doc/reference')
 
-if not meson.is_subproject()
+if can_add_dist_script
   # Add a ChangeLog file to the distribution directory.
-  # (add_dist_script() is not allowed in a subproject)
   meson.add_dist_script(
     python3.path(), dist_changelog_py,
     project_source_root,
@@ -232,8 +234,9 @@ if not meson.is_subproject()
     project_source_root,
     'untracked' / 'build_scripts',
   )
-else
-  # This is a subproject.
+endif
+
+if meson.is_subproject()
   atkmm_dep = declare_dependency(
     dependencies: atkmm_own_dep,
     variables: {