Merge branches 'vala-fix-pr11222' and 'vala-fix-pr11229' into maint

* vala-fix-pr11222:
  vala: fix vapi files handling
  vala: test vapi files handling (still failing)

* vala-fix-pr11229:
  vala: fix distcheck with c/vala mixed projects

diff --cc automake.in
index 765a769,836680a..921a6ae
--- 1/automake.in
--- 2/automake.in
+++ b/automake.in
@@@ -6039,11 -6039,14 +6039,14 @@@ sub lang_vala_finish_target ($$
    my $var = var "${derived}_SOURCES";
    return unless $var;
  
 -  my @vala_sources = grep { /\.vala$/ } ($var->value_as_list_recursive);
 +  my @vala_sources = grep { /\.(vala|vapi)$/ } ($var->value_as_list_recursive);
  
+   # For automake bug#11229.
+   return unless @vala_sources;
+ 
    foreach my $vala_file (@vala_sources)
      {
 -      (my $c_file = $vala_file) =~ s/(.*)\.vala$/$1.c/;
 +      my $c_file = $vala_file;
        $output_rules .= "\$(srcdir)/$c_file: \$(srcdir)/${derived}_vala.stamp\n"
          . "\t\@if test -f \$@; then :; else rm -f \$(srcdir)/${derived}_vala.stamp; fi\n"
          . "\t\@if test -f \$@; then :; else \\\n"