[shotwell] Use meson's vcs_tag() for the git hash

[Jens Georg <jensgeorg src gnome org>]

commit e04e37f6fefdaf6e2156e968249e95e1faeb8b1a
Author: Jens Georg <mail jensge org>
Date:   Sun Sep 23 12:13:34 2018 +0200

    Use meson's vcs_tag() for the git hash

 git-hash           |  4 ----
 meson.build        | 10 +++-------
 src/AppWindow.vala |  2 +-
 src/Resources.vala |  4 ----
 src/main.vala      |  4 ++--
 version.h.in       |  3 +++
 6 files changed, 9 insertions(+), 18 deletions(-)
---
diff --git a/meson.build b/meson.build
index dbe13f53..44d001e4 100644
--- a/meson.build
+++ b/meson.build
@@ -20,7 +20,8 @@ vapi_incdir = include_directories('vapi')
 shotwell_plugin_dir = join_paths(get_option('libdir'), 'shotwell', 'plugins', 'builtin')
 
 add_global_arguments(['-DHAVE_CONFIG_H=1'],
-                     ['-include'], ['config.h'], language : 'c')
+                     ['-include'], ['config.h'],
+                     ['-include'], ['version.h'], language : 'c')
 add_global_arguments(['--target-glib=2.40',
                       '--vapidir=@0@'.format(join_paths(meson.current_source_dir(),
                         'vapi')),
@@ -29,12 +30,7 @@ add_global_arguments(['--target-glib=2.40',
                       '--enable-experimental',
                       '--enable-deprecated'], language : 'vala')
 
-gitver = run_command(find_program('git-hash'))
-if gitver.returncode() == 0
-  add_global_arguments(['-D_GIT_VERSION="@0@"'.format(gitver.stdout().strip())],
-    language : 'c')
-  add_global_arguments(['--define=_GITVERSION'], language : 'vala')
-endif
+vcs_tag(command: ['git', 'rev-parse', 'HEAD'], input: 'version.h.in', output: 'version.h', fallback: '')
 
 gtk = dependency('gtk+-3.0', version : '>= 3.22')
 gio = dependency('gio-2.0', version: '>= 2.40')
diff --git a/src/AppWindow.vala b/src/AppWindow.vala
index e50a254f..a9b3ceba 100644
--- a/src/AppWindow.vala
+++ b/src/AppWindow.vala
@@ -594,7 +594,7 @@ public abstract class AppWindow : PageWindow {
     protected void on_about() {
         const string[] artists = { "Braunschweiger Löwe created by Magnus Manske., CC BY-SA 3.0, 
https://commons.wikimedia.org/w/index.php?curid=109735";, null };
         Gtk.show_about_dialog(this,
-            "version", Resources.APP_VERSION,
+            "version", Resources.APP_VERSION + (Resources.GIT_VERSION != "" ? " — " + Resources.GIT_VERSION 
: ""),
             "comments", get_app_role(),
             "copyright", Resources.COPYRIGHT,
             "website", Resources.HOME_URL,
diff --git a/src/Resources.vala b/src/Resources.vala
index 909964e7..821819ff 100644
--- a/src/Resources.vala
+++ b/src/Resources.vala
@@ -18,11 +18,7 @@ namespace Resources {
     public const string APP_DIRECT_ROLE = _("Photo Viewer");
     public const string APP_VERSION = _VERSION;
 
-#if _GITVERSION
     public const string? GIT_VERSION = _GIT_VERSION;
-#else
-    public const string? GIT_VERSION = null;
-#endif
 
     public const string COPYRIGHT = _("Copyright 2016 Software Freedom Conservancy Inc.");
     public const string APP_GETTEXT_PACKAGE = GETTEXT_PACKAGE;
diff --git a/src/main.vala b/src/main.vala
index 8ae41fc0..68822435 100644
--- a/src/main.vala
+++ b/src/main.vala
@@ -383,7 +383,7 @@ void main(string[] args) {
     }
 
     if (CommandlineOptions.show_version) {
-        if (Resources.GIT_VERSION != null)
+        if (Resources.GIT_VERSION != "")
             print("%s %s (%s)\n", Resources.APP_TITLE, Resources.APP_VERSION, Resources.GIT_VERSION);
         else
             print("%s %s\n", Resources.APP_TITLE, Resources.APP_VERSION);
@@ -415,7 +415,7 @@ void main(string[] args) {
     
     Debug.init(is_string_empty(filename) ? Debug.LIBRARY_PREFIX : Debug.VIEWER_PREFIX);
 
-    if (Resources.GIT_VERSION != null)
+    if (Resources.GIT_VERSION != "")
         message("Shotwell %s %s (%s)",
             is_string_empty(filename) ? Resources.APP_LIBRARY_ROLE : Resources.APP_DIRECT_ROLE,
             Resources.APP_VERSION, Resources.GIT_VERSION);
diff --git a/version.h.in b/version.h.in
new file mode 100644
index 00000000..fe25b696
--- /dev/null
+++ b/version.h.in
@@ -0,0 +1,3 @@
+#pragma once
+
+#define _GIT_VERSION "@VCS_TAG@"