[libgit2-glib] meson: add support for macOS dylib versioning

[Alberto Fanjul <albfan src gnome org>]

commit 6110143f2f0784d7fcfc883fad92869c7a65782e
Author: Tom Schoonjans <Tom Schoonjans diamond ac uk>
Date:   Mon Apr 22 12:39:37 2019 +0100

    meson: add support for macOS dylib versioning

 libgit2-glib/meson.build | 1 +
 meson.build              | 1 +
 2 files changed, 2 insertions(+)
---
diff --git a/libgit2-glib/meson.build b/libgit2-glib/meson.build
index 6314a4d..9158178 100644
--- a/libgit2-glib/meson.build
+++ b/libgit2-glib/meson.build
@@ -209,6 +209,7 @@ libgit2_glib = shared_library(
   'git2-glib-' + libgit2_glib_api_version,
   version: libversion,
   soversion: soversion,
+  darwin_versions: darwin_versions,
   sources: sources + enum_sources,
   include_directories: top_inc,
   dependencies: platform_deps,
diff --git a/meson.build b/meson.build
index 6cddb2d..b24c268 100644
--- a/meson.build
+++ b/meson.build
@@ -35,6 +35,7 @@ soversion = 0
 current = libgit2_glib_minor_version * 100 + libgit2_glib_micro_version - libgit2_glib_interface_age
 revision = libgit2_glib_interface_age
 libversion = '@0@.@1@.@2@'.format(soversion, current, revision)
+darwin_versions = [current + 1, '@0@.@1@'.format(current + 1, revision)]
 
 libgit2_glib_prefix = get_option('prefix')
 libgit2_glib_libdir = get_option('libdir')