configure: Allow to detect git checkout if .git is not a directory

E.g. if you use openvpn as a git submodule, it can be a
file that points to the parent's git directory.

The changes to Makefile.am are not strictly required, they
still work with that case, but I wanted to keep the usage
consistent.

Change-Id: I9b7a3df012e7606ddb04a944e3fa33247180e8dd
Signed-off-by: Frank Lichtenheld <[email protected]>
Acked-by: Arne Schwabe <[email protected]>
Acked-by: Yuriy Darnobyt <[email protected]>
Message-Id: <[email protected]>
URL: https://www.mail-archive.com/[email protected]/msg29092.html
Signed-off-by: Gert Doering <[email protected]>

Author: flichtenheld

Makefile.am

@@ -75,9 +75,9 @@ dist_noinst_DATA = \
 	README.wolfssl
 
 config-version.h:
-	@CONFIGURE_GIT_CHFILES="`GIT_DIR=\"$(top_srcdir)/.git\" $(GIT) diff-files --name-status -r --ignore-submodules --quiet -- || echo \"+\"`"; \
-	CONFIGURE_GIT_UNCOMMITTED="`GIT_DIR=\"$(top_srcdir)/.git\" $(GIT) diff-index --cached  --quiet --ignore-submodules HEAD || echo \"*\"`"; \
-	CONFIGURE_GIT_REVISION="`GIT_DIR=\"$(top_srcdir)/.git\" $(GIT) rev-parse --symbolic-full-name HEAD | cut -d/ -f3-`/`GIT_DIR=\"$(top_srcdir)/.git\" $(GIT) rev-parse --short=16 HEAD`"; \
+	@CONFIGURE_GIT_CHFILES="`$(GIT) -C \"$(top_srcdir)\" diff-files --name-status -r --ignore-submodules --quiet -- || echo \"+\"`"; \
+	CONFIGURE_GIT_UNCOMMITTED="`$(GIT) -C \"$(top_srcdir)\" diff-index --cached  --quiet --ignore-submodules HEAD || echo \"*\"`"; \
+	CONFIGURE_GIT_REVISION="`$(GIT) -C \"$(top_srcdir)\" rev-parse --symbolic-full-name HEAD | cut -d/ -f3-`/`$(GIT) -C \"$(top_srcdir)\" rev-parse --short=16 HEAD`"; \
 	echo "#define CONFIGURE_GIT_REVISION \"$${CONFIGURE_GIT_REVISION}\"" > config-version.h.tmp; \
 	echo "#define CONFIGURE_GIT_FLAGS \"$${CONFIGURE_GIT_CHFILES}$${CONFIGURE_GIT_UNCOMMITTED}\"" >> config-version.h.tmp
 

configure.ac

@@ -1308,9 +1308,11 @@ fi
 
 AC_MSG_CHECKING([git checkout])
 GIT_CHECKOUT="no"
-if test -n "${GIT}" -a -d "${srcdir}/.git"; then
-	AC_DEFINE([HAVE_CONFIG_VERSION_H], [1], [extra version available in config-version.h])
-	GIT_CHECKOUT="yes"
+if test -n "${GIT}"; then
+	if ${GIT} -C "$srcdir" rev-parse --is-inside-work-tree >/dev/null 2>&1; then
+		AC_DEFINE([HAVE_CONFIG_VERSION_H], [1], [extra version available in config-version.h])
+		GIT_CHECKOUT="yes"
+	fi
 fi
 AC_MSG_RESULT([${GIT_CHECKOUT}])