[gtk] meson: Only use HarfBuzz fallback when needed

[Chun-wei Fan <fanchunwei src gnome org>]

commit 88086ea91aa19dc8b8a20b0e560d593cbd9f45e2
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Fri Apr 12 18:08:36 2019 +0800

    meson: Only use HarfBuzz fallback when needed
    
    The current Meson releases have broken CMake support, meaning that it is
    likely that HarfBuzz could not be located for Visual Studio builds
    unless one handcrafts pkg-config files for it, which is both tedious and
    error-prone.
    
    Instead, use the existing mechanism for looking for the HarfBuzz headers
    and libraries on Visual Studio first when it could not be found via
    dependency(), and then use the fallback if it still could not be found.

 meson.build | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)
---
diff --git a/meson.build b/meson.build
index 9c2142d166..ab30f90098 100644
--- a/meson.build
+++ b/meson.build
@@ -376,8 +376,7 @@ pixbuf_dep     = dependency('gdk-pixbuf-2.0', version: gdk_pixbuf_req,
 epoxy_dep      = dependency('epoxy', version: epoxy_req,
                             fallback: ['libepoxy', 'libepoxy_dep'])
 atk_dep        = dependency('atk', version: atk_req)
-harfbuzz_dep   = dependency('harfbuzz', version: '>= 0.9', required: false,
-                            fallback: ['harfbuzz', 'libharfbuzz_dep'])
+harfbuzz_dep   = dependency('harfbuzz', version: '>= 0.9', required: false)
 xkbdep         = dependency('xkbcommon', version: xkbcommon_req, required: wayland_enabled)
 graphene_dep   = dependency('graphene-gobject-1.0', version: graphene_req,
                             fallback: ['graphene', 'graphene_dep'])
@@ -460,6 +459,11 @@ if cc.get_id() == 'msvc'
   endif
 endif
 
+if not harfbuzz_dep.found()
+  harfbuzz_dep = dependency('harfbuzz', version: '>= 0.9', required: false,
+                            fallback: ['harfbuzz', 'libharfbuzz_dep'])
+endif
+
 cdata.set('HAVE_HARFBUZZ', harfbuzz_dep.found())
 cdata.set('HAVE_PANGOFT', pangoft_dep.found())