gdbus_codegen: Guess the output list for docbook generation

We were setting it to a file list that would always be wrong, and
always out of date since it would never exist.

However, the output list is not predictable. It usually has a 1-1
relationship with the input XML files, but it may not.

This must be fixed later with API for users to provide the output
names.

See: https://github.com/mesonbuild/meson/pull/3539

mesonbuild/modules/gnome.py

@@ -938,9 +938,13 @@ This will become a hard error in the future.''')
 
                 docbook_cmd = cmd + ['--output-directory', '@OUTDIR@', '--generate-docbook', docbook, '@INPUT@']
 
+                # The docbook output is always ${docbook}-${name_of_xml_file}
                 output = namebase + '-docbook'
+                outputs = []
+                for f in xml_files:
+                    outputs.append('{}-{}'.format(docbook, f))
                 custom_kwargs = {'input': xml_files,
-                                 'output': output,
+                                 'output': outputs,
                                  'command': docbook_cmd,
                                  'build_by_default': build_by_default
                                  }

run_unittests.py

@@ -686,8 +686,10 @@ class BasePlatformTests(unittest.TestCase):
         cmds = [l[len(prefix):].split() for l in log if l.startswith(prefix)]
         return cmds
 
-    def introspect(self, arg):
-        out = subprocess.check_output(self.mintro_command + [arg, self.builddir],
+    def introspect(self, args):
+        if isinstance(args, str):
+            args = [args]
+        out = subprocess.check_output(self.mintro_command + args + [self.builddir],
                                       universal_newlines=True)
         return json.loads(out)
 
@@ -2819,6 +2821,18 @@ class LinuxlikeTests(BasePlatformTests):
                 gobject_found = True
         self.assertTrue(glib_found)
         self.assertTrue(gobject_found)
+        if subprocess.call(['pkg-config', '--exists', 'glib-2.0 >= 2.56.2']) != 0:
+            raise unittest.SkipTest('glib >= 2.56.2 needed for the rest')
+        targets = self.introspect('--targets')
+        docbook_target = None
+        for t in targets:
+            if t['name'] == 'generated-gdbus-docbook':
+                docbook_target = t
+                break
+        self.assertIsInstance(docbook_target, dict)
+        ifile = self.introspect(['--target-files', 'generated-gdbus-docbook@cus'])[0]
+        self.assertEqual(t['filename'], 'gdbus/generated-gdbus-doc-' + ifile)
+
 
     def test_build_rpath(self):
         if is_cygwin():

test cases/frameworks/10 gtk-doc/doc/meson.build

@@ -5,8 +5,7 @@ version_xml = configure_file(input : 'version.xml.in',
                              configuration : cdata)
 
 gnome.gtkdoc('foobar',
-  version_xml,
   src_dir : inc,
   main_sgml : 'foobar-docs.sgml',
-  content_files : docbook,
+  content_files : [docbook, version_xml],
   install : true)