[sushi/wip/lantw/build-fix-build-when-wayland-is-disabled] build: fix build when wayland is disabled

[Ting-Wei Lan <lantw src gnome org>]

commit 5cf246dadab096344b52dfba5034d6edbe7c567c
Author: Ting-Wei Lan <lantw src gnome org>
Date:   Sat Sep 28 16:16:10 2019 +0800

    build: fix build when wayland is disabled
    
    Don't define HAVE_GTK_X11 or HAVE_GTK_WAYLAND when the dependency can't
    be found. Otherwise, #ifdef checks in code are useless because results
    of checks are always true.

 src/libsushi/meson.build | 26 ++++++++++++++++++++------
 1 file changed, 20 insertions(+), 6 deletions(-)
---
diff --git a/src/libsushi/meson.build b/src/libsushi/meson.build
index 4f15335..fe2e874 100644
--- a/src/libsushi/meson.build
+++ b/src/libsushi/meson.build
@@ -1,17 +1,31 @@
 config_data = configuration_data()
-config_data.set10('HAVE_GTK_X11', gtk_x11_dep.found())
-config_data.set10('HAVE_GTK_WAYLAND', gtk_wayland_dep.found())
+if gtk_x11_dep.found()
+  config_data.set('HAVE_GTK_X11', 1)
+endif
+if gtk_wayland_dep.found()
+  config_data.set('HAVE_GTK_WAYLAND', 1)
+endif
 configure_file(output: 'config.h', configuration: config_data)
 
 externalwindow_sources = [
   'externalwindow.c',
   'externalwindow.h',
-  'externalwindow-wayland.c',
-  'externalwindow-wayland.h',
-  'externalwindow-x11.c',
-  'externalwindow-x11.h',
 ]
 
+if gtk_x11_dep.found()
+  externalwindow_sources += [
+    'externalwindow-x11.c',
+    'externalwindow-x11.h',
+  ]
+endif
+
+if gtk_wayland_dep.found()
+  externalwindow_sources += [
+    'externalwindow-wayland.c',
+    'externalwindow-wayland.h',
+  ]
+endif
+
 libsushi_deps = [
   epoxy_dep,
   evince_document_dep,