build: Make libportal a meson subproject

This has a few advantages:
* there is a circular dependency between x-d-p and libportal which we
  can break by building a specific commit from any repo which isn't
  upstream, yet
* the version required for the tests will automatically reach developers
* CI and local builds use the same version

.github/workflows/build-and-test.yml

@@ -41,30 +41,6 @@ jobs:
       - name: Check POTFILES.in
         run: .github/workflows/check-potfiles.sh
 
-      - name: Check out libportal fork with a similarly named branch
-        id: libportal-branched
-        uses: actions/checkout@v4
-        continue-on-error: true
-        with:
-          repository: ${{ github.actor }}/libportal
-          ref: ${{ github.head_ref || github.ref_name }}
-          path: libportal
-
-      - name: Check out libportal default branch
-        if: steps.libportal-branched.outcome == 'failure'
-        uses: actions/checkout@v4
-        with:
-          repository: flatpak/libportal
-          path: libportal
-
-      - name: Build libportal
-        run: |
-          meson setup libportal _build_libportal $MESON_OPTIONS
-          meson compile -C _build_libportal
-          meson install -C _build_libportal
-        env:
-          MESON_OPTIONS: --prefix=/usr -Ddocs=false -Dintrospection=false -Dtests=false
-
       - name: Build xdg-desktop-portal
         run: |
           meson setup _build $MESON_OPTIONS

.gitignore

@@ -1 +1,2 @@
 __pycache__
+subprojects/libportal/

meson.build

@@ -112,8 +112,6 @@ gst_pbutils_dep = dependency('gstreamer-pbutils-1.0')
 geoclue_dep = dependency('libgeoclue-2.0',
                          version: '>= 2.5.2',
                          required: get_option('geoclue'))
-libportal_dep = dependency('libportal',
-                           required: get_option('libportal'))
 pipewire_dep = dependency('libpipewire-0.3', version: '>= 0.2.90')
 libsystemd_dep = dependency('libsystemd', required: get_option('systemd'))
 
@@ -129,7 +127,23 @@ if not bwrap.found()
     ''')
 endif
 
-have_libportal = libportal_dep.found()
+if get_option('libportal-subproject')
+  libportal_proj = subproject(
+    'libportal',
+    default_options: [
+      'introspection=false',
+      'vapi=false',
+      'docs=false',
+      'tests=false',
+    ],
+  )
+  libportal_dep = libportal_proj.get_variable('libportal_dep')
+else
+  libportal_dep = dependency('libportal', required: false)
+endif
+
+libportal_option = get_option('libportal').require(libportal_dep.found())
+have_libportal = libportal_option.allowed()
 if have_libportal
   config_h.set('HAVE_LIBPORTAL', 1)
 endif

meson_options.txt

@@ -18,6 +18,10 @@ option('libportal',
        type: 'feature',
        value: 'auto',
        description: 'Enable libportal support. Needed for tests')
+option('libportal-subproject',
+        type: 'boolean',
+        value: true,
+        description: 'Use libportal as subproject')
 option('geoclue',
        type: 'feature',
        value: 'auto',

subprojects/libportal.wrap

@@ -0,0 +1,4 @@
+[wrap-git]
+directory=libportal
+url=https://github.com/jsparber/libportal.git
+revision=implement_v2_notification_spec