From: Sven Verdoolaege <skimo@kotnet.org>
Date: Mon, 23 Dec 2013 09:12:10 +0000 (+0100)
Subject: AX_DETECT_GIT_HEAD: detect git version with newer versions of git
X-Git-Tag: isl-0.13~100
X-Git-Url: https://repo.or.cz/w/isl.git/commitdiff_plain/26658ec1992310b8ccf3290a9a474f42f3ee22d9

AX_DETECT_GIT_HEAD: detect git version with newer versions of git

In particular, if isl is used as a submodule, then in newer versions
of git, .git may be a file containing the path of the real directory
that has the repository.

Signed-off-by: Sven Verdoolaege <skimo@kotnet.org>
---

diff --git a/m4/ax_detect_git_head.m4 b/m4/ax_detect_git_head.m4
index d5859835..c3326277 100644
--- a/m4/ax_detect_git_head.m4
+++ b/m4/ax_detect_git_head.m4
@@ -2,7 +2,12 @@ AC_DEFUN([AX_DETECT_GIT_HEAD], [
 	AC_SUBST(GIT_HEAD_ID)
 	AC_SUBST(GIT_HEAD)
 	AC_SUBST(GIT_HEAD_VERSION)
-	if test -f $srcdir/.git/HEAD; then
+	if test -f $srcdir/.git; then
+		gitdir=`GIT_DIR=$srcdir/.git git rev-parse --git-dir`
+		GIT_HEAD="$gitdir/index"
+		GIT_REPO="$gitdir"
+		GIT_HEAD_ID=`GIT_DIR=$GIT_REPO git describe`
+	elif test -f $srcdir/.git/HEAD; then
 		GIT_HEAD="$srcdir/.git/index"
 		GIT_REPO="$srcdir/.git"
 		GIT_HEAD_ID=`GIT_DIR=$GIT_REPO git describe`