[libsoup] Meson: Fallback to glib subproject

[Tomas Popela <tpopela src gnome org>]

commit 94fe681f49c1bb5ff501a01b9a079d3f6e87b51a
Author: Xavier Claessens <xavier claessens collabora com>
Date:   Wed Dec 5 14:57:39 2018 -0500

    Meson: Fallback to glib subproject
    
    When libsoup is built as a Meson subproject, it is possible to parent
    project also built glib as subproject. In that case we should not use
    the system glib.

 meson.build | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)
---
diff --git a/meson.build b/meson.build
index 3d4e650f..66337c1f 100644
--- a/meson.build
+++ b/meson.build
@@ -55,9 +55,12 @@ endif
 add_project_arguments(common_flags, language : 'c')
 
 glib_required_version = '>= 2.38'
-glib_dep = [dependency('glib-2.0', version : glib_required_version),
-            dependency('gobject-2.0', version : glib_required_version),
-            dependency('gio-2.0', version : glib_required_version)]
+glib_dep = [dependency('glib-2.0', version : glib_required_version,
+                       fallback: ['glib', 'libglib_dep']),
+            dependency('gobject-2.0', version : glib_required_version,
+                       fallback: ['glib', 'libgobject_dep']),
+            dependency('gio-2.0', version : glib_required_version,
+                       fallback: ['glib', 'libgio_dep'])]
 
 sqlite_dep = dependency('sqlite3', required: cc.get_id() != 'msvc')