build: check for .git in configure.ac

Don't error out when someone tries using --with-pkg-git-version on
something that isn't actually a git checkout (like a dist tarball).

Signed-off-by: David Lamparter <equinox@opensourcerouting.org>

diff --git a/configure.ac b/configure.ac
index c1a4d8cdd2042bf01f6c6676bd60368d576fde8d..405693c9ba5f7e0b97d9c8de6b4a89cc259f23c5 100755 (executable)
--- a/configure.ac
+++ b/configure.ac
@@ -195,10 +195,7 @@ AC_ARG_WITH(pkg-extra-version,
        [EXTRAVERSION=$withval],)
 AC_ARG_WITH(pkg-git-version,
        AS_HELP_STRING([--with-pkg-git-version], [add git information to MOTD and build version string]),
-       [ if test "x$withval" != "xno"; then
-               with_pkg_git_version="1"
-               AC_DEFINE(GIT_VERSION, [1], [include git version info])
-       fi ],)
+       [ test "x$withval" != "xno" && with_pkg_git_version="yes" ])
 AC_ARG_ENABLE(vtysh,
 [  --enable-vtysh          include integrated vty shell for Quagga])
 AC_ARG_ENABLE(ipv6,
@@ -410,7 +407,14 @@ if test "x${EXTRAVERSION}" != "x" ; then
   PACKAGE_STRING="${PACKAGE_STRING}${EXTRAVERSION}"
 fi
 
-AM_CONDITIONAL([GIT_VERSION], [test "x$with_pkg_git_version" != "x"])
+if test "x$with_pkg_git_version" = "xyes"; then
+       if test -d "${srcdir}/.git"; then
+               AC_DEFINE(GIT_VERSION, [1], [include git version info])
+       else    with_pkg_git_version="no"
+               AC_MSG_WARN([--with-pkg-git-version given, but this is not a git checkout])
+       fi
+fi
+AM_CONDITIONAL([GIT_VERSION], [test "x$with_pkg_git_version" = "xyes"])
 
 dnl ------------------------------------
 dnl Check C keywords and standard  types