[glib: 6/9] doc: Add gtk-doc subproject fallback

[Philip Withnall <pwithnall src gnome org>]

commit 5bd78907a7ca1e82484430c7e38331ad40a76ae7
Author: Xavier Claessens <xavier claessens collabora com>
Date:   Fri Dec 13 13:46:00 2019 -0500

    doc: Add gtk-doc subproject fallback
    
    Now that we require Meson 0.52 to build the doc, we can also pull
    gtk-doc as subproject when missing from the system. This requires
    to pull gtk-doc master because needed changes there haven't been release
    yet.

 docs/reference/meson.build | 4 +++-
 subprojects/gtk-doc.wrap   | 4 ++++
 2 files changed, 7 insertions(+), 1 deletion(-)
---
diff --git a/docs/reference/meson.build b/docs/reference/meson.build
index bdc22a0c3..0dd821ada 100644
--- a/docs/reference/meson.build
+++ b/docs/reference/meson.build
@@ -50,7 +50,9 @@ if get_option('gtk_doc')
   endif
   # Check we have the minimum gtk-doc version required. Older versions won't
   # generate correct documentation.
-  dependency('gtk-doc', version : '>=1.32')
+  dependency('gtk-doc', version : '>=1.32',
+    fallback : ['gtk-doc', 'dummy_dep'],
+    default_options : ['tests=false'])
 endif
 
 subdir('gio')
diff --git a/subprojects/gtk-doc.wrap b/subprojects/gtk-doc.wrap
new file mode 100644
index 000000000..7469d027b
--- /dev/null
+++ b/subprojects/gtk-doc.wrap
@@ -0,0 +1,4 @@
+[wrap-git]
+directory=gtk-doc
+url=https://gitlab.gnome.org/GNOME/gtk-doc.git
+revision=master