xwayland: remove find_program() fallback when dep is not found

The dep allows us to check dep variables to discover supported
features. With the binary we assume none of the features are
supported. If a user forgets to install the pkg-config file (e.g.
because it's in a split package) we end up incorrectly disabling
all features. Instead let's error out.

.builds/alpine.yml

@@ -15,7 +15,7 @@ packages:
   - xcb-util-image-dev
   - xcb-util-renderutil-dev
   - xcb-util-wm-dev
-  - xwayland
+  - xwayland-dev
   - libseat-dev
   - hwdata
 sources:

.builds/freebsd.yml

@@ -22,7 +22,7 @@ packages:
   - x11/xcb-util-errors
   - x11/xcb-util-renderutil
   - x11/xcb-util-wm
-  - x11-servers/xwayland
+  - x11-servers/xwayland-devel
   - sysutils/seatd
   - gmake
   - hwdata

xwayland/meson.build

@@ -19,17 +19,9 @@ if not get_option('xwayland').disabled()
 	msg += 'Required for Xwayland support.'
 endif
 
-xwayland = dependency('xwayland', required: false)
+xwayland = dependency('xwayland', required: get_option('xwayland'))
 if not xwayland.found()
-	# There's no Xwayland release with the pkg-config file shipped yet.
-	xwayland_prog = find_program('Xwayland', required: false)
-	if not xwayland_prog.found()
-		if get_option('xwayland').enabled()
-			error('\n'.join(msg).format('xwayland'))
-		else
 	subdir_done()
-		endif
-	endif
 endif
 
 foreach lib : xwayland_required
@@ -69,22 +61,9 @@ xwayland_feature_names = [
 	'terminate_delay',
 ]
 
-xwayland_features = {}
-if xwayland.found()
-	xwayland_path = xwayland.get_variable('xwayland')
-	foreach name : xwayland_feature_names
+internal_config.set_quoted('XWAYLAND_PATH', xwayland.get_variable('xwayland'))
+foreach name : xwayland_feature_names
 	have = xwayland.get_variable('have_' + name, default_value: 'false') == 'true'
-		xwayland_features += { name: have }
-	endforeach
-else
-	xwayland_path = xwayland_prog.full_path()
-	foreach name : xwayland_feature_names
-		xwayland_features += { name: false }
-	endforeach
-endif
-
-internal_config.set_quoted('XWAYLAND_PATH', xwayland_path)
-foreach name, have : xwayland_features
 	internal_config.set10('HAVE_XWAYLAND_' + name.to_upper(), have)
 endforeach