[gnome-shell-extensions] classic: Install the session for Wayland and ship override sessions

[Marge Bot <marge-bot src gnome org>]

commit eb517c851777067087c3bf067c2baf10dcaf4128
Author: Neal Gompa <ngompa fedoraproject org>
Date:   Fri Oct 29 09:37:33 2021 -0400

    classic: Install the session for Wayland and ship override sessions
    
    The regular GNOME session ships with three options:
    
    * GNOME
    * GNOME on Wayland (available when GDM starts in X11)
    * GNOME on Xorg (available when GDM starts in Wayland)
    
    The main GNOME session is set up so it works to match how GDM starts,
    so GNOME is on Wayland if GDM is (or GNOME is on X11 if GDM is).
    
    For GNOME Classic, we are missing this setup, so port this behavior
    over from the GNOME session setup.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell-extensions/-/merge_requests/195>

 data/gnome-classic-wayland.desktop.in |  8 +++++++
 data/gnome-classic-xorg.desktop.in    |  8 +++++++
 data/meson.build                      | 40 +++++++++++++++++++++++++++--------
 meson.build                           |  5 +++++
 meson/session-post-install.py         | 20 ++++++++++++++++++
 5 files changed, 72 insertions(+), 9 deletions(-)
---
diff --git a/data/gnome-classic-wayland.desktop.in b/data/gnome-classic-wayland.desktop.in
new file mode 100644
index 0000000..7287c68
--- /dev/null
+++ b/data/gnome-classic-wayland.desktop.in
@@ -0,0 +1,8 @@
+[Desktop Entry]
+Name=GNOME Classic on Wayland
+Comment=This session logs you into GNOME Classic
+Exec=env GNOME_SHELL_SESSION_MODE=classic gnome-session
+TryExec=gnome-session
+Type=Application
+DesktopNames=GNOME-Classic;GNOME;
+X-GDM-SessionRegisters=true
diff --git a/data/gnome-classic-xorg.desktop.in b/data/gnome-classic-xorg.desktop.in
new file mode 100644
index 0000000..5fb338a
--- /dev/null
+++ b/data/gnome-classic-xorg.desktop.in
@@ -0,0 +1,8 @@
+[Desktop Entry]
+Name=GNOME Classic on Xorg
+Comment=This session logs you into GNOME Classic
+Exec=env GNOME_SHELL_SESSION_MODE=classic gnome-session
+TryExec=gnome-session
+Type=Application
+DesktopNames=GNOME-Classic;GNOME;
+X-GDM-SessionRegisters=true
diff --git a/data/meson.build b/data/meson.build
index 27f4287..47fe798 100644
--- a/data/meson.build
+++ b/data/meson.build
@@ -1,12 +1,34 @@
-session_desktop = 'gnome-classic.desktop'
-i18n.merge_file('',
-  input:  session_desktop + '.in',
-  output: session_desktop,
-  po_dir: '../po',
-  install: true,
-  install_dir: xsessiondir,
-  type: 'desktop'
-)
+session_desktop_base = 'gnome-classic'
+
+session_desktops = [
+  session_desktop_base,
+  session_desktop_base + '-xorg',
+  session_desktop_base + '-wayland',
+]
+
+foreach name: session_desktops
+    session_desktop = name + '.desktop'
+    if name.endswith('-xorg')
+        session_instdir = xsessiondir
+    elif name.endswith('-wayland')
+        session_instdir = wlsessiondir
+    else
+        # FIXME: The same target can not be copied into two directories.
+        #        There is a workaround in meson/session-post-install.py until proper
+        #        solution arises:
+        #        https://github.com/mesonbuild/meson/issues/2416
+        session_instdir = xsessiondir
+        #session_instdir = [ xesssiondir, wlsessiondir ]
+    endif
+    i18n.merge_file('',
+      input:  session_desktop + '.in',
+      output: session_desktop,
+      po_dir: '../po',
+      install: true,
+      install_dir: session_instdir,
+      type: 'desktop'
+    )
+endforeach
 
 classic_uuids = []
 foreach e : classic_extensions
diff --git a/meson.build b/meson.build
index 8f2afda..33006b3 100644
--- a/meson.build
+++ b/meson.build
@@ -20,6 +20,7 @@ themedir = join_paths(shelldir, 'theme')
 schemadir = join_paths(datadir, 'glib-2.0', 'schemas')
 sessiondir = join_paths(datadir, 'gnome-session', 'sessions')
 xsessiondir = join_paths(datadir, 'xsessions')
+wlsessiondir = join_paths(datadir, 'wayland-sessions')
 
 ver_arr = meson.project_version().split('.')
 shell_version = ver_arr[0]
@@ -83,6 +84,10 @@ endforeach
 
 if classic_mode_enabled
   subdir('data')
+  meson.add_install_script(
+    'meson/session-post-install.py',
+    join_paths(get_option('prefix'), datadir)
+  )
 endif
 
 subdir('extensions')
diff --git a/meson/session-post-install.py b/meson/session-post-install.py
new file mode 100755
index 0000000..36abe5e
--- /dev/null
+++ b/meson/session-post-install.py
@@ -0,0 +1,20 @@
+#!/usr/bin/env python3
+
+import os
+import shutil
+import sys
+
+if os.environ.get('DESTDIR'):
+  install_root = os.environ.get('DESTDIR') + os.path.abspath(sys.argv[1])
+else:
+  install_root = sys.argv[1]
+
+# FIXME: Meson is unable to copy a generated target file:
+#        https://groups.google.com/forum/#!topic/mesonbuild/3iIoYPrN4P0
+dst_dir = os.path.join(install_root, 'wayland-sessions')
+if not os.path.exists(dst_dir):
+  os.makedirs(dst_dir)
+
+src = os.path.join(install_root, 'xsessions', 'gnome-classic.desktop')
+dst = os.path.join(dst_dir, 'gnome-classic.desktop')
+shutil.copyfile(src, dst)