[network-manager-applet] build: embed NM_GIT_SHA in generated "configure" script

[Thomas Haller <thaller src gnome org>]

commit 5158105c11aae6b4c358aafd1bb8eb004555f346
Author: Thomas Haller <thaller redhat com>
Date:   Mon Aug 10 14:24:25 2015 +0200

    build: embed NM_GIT_SHA in generated "configure" script
    
    This detects the current git commit id and embeds it in the
    generated "configure" script. As the configure script is included
    in the dist-tarball, we can detect the original git commit from
    a tarball.

 configure.ac |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index 056129a..e3e6b15 100644
--- a/configure.ac
+++ b/configure.ac
@@ -25,6 +25,10 @@ dnl Initialize libtool
 LT_PREREQ([2.2.6])
 LT_INIT
 
+m4_define([nm_git_sha], [m4_esyscmd([ ( [ -d ./.git/ ] && [ "$(readlink -f ./.git/)" = "$(readlink -f "$(git 
rev-parse --git-dir 2>/dev/null)" 2>/dev/null)" ] && git rev-parse --verify -q HEAD 2>/dev/null ) || true ])])
+NM_GIT_SHA=nm_git_sha
+AC_DEFINE_UNQUOTED(NM_GIT_SHA,"$NM_GIT_SHA",[git commit id of the original source code version])
+
 dnl
 dnl Checks for typedefs, structures, and compiler characteristics.
 dnl