8 files changed, 91 insertions, 2 deletions
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4174ebb8..0a19fac1 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -38,6 +38,32 @@ if(WITH_OGG)
     set(OGG_PACKAGE "ogg")
 endif()
 
+find_program (HAVE_GIT git)
+
+if(HAVE_GIT)
+    execute_process(
+        COMMAND git describe --tags --exact-match
+        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_COMMIT_TAG
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        ERROR_QUIET
+        )
+    execute_process(
+        COMMAND git log -1 --pretty=format:%h
+        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_COMMIT_HASH
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        ERROR_QUIET
+        )
+    execute_process(
+        COMMAND git log -1 --pretty=format:%cd --date=format:%Y%m%d
+        WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+        OUTPUT_VARIABLE GIT_COMMIT_DATE
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        ERROR_QUIET
+        )
+endif()
+
 find_package(Iconv)
 set(HAVE_ICONV ${Iconv_FOUND})
 
diff --git a/Makefile.am b/Makefile.am
index 7729c36f..510c094c 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -59,4 +59,6 @@ EXTRA_DIST = \
 	ltmain.sh \
 	strip_non_asm_libtool_args.sh
 
+DISTCHECK_CONFIGURE_FLAGS = '--disable-version-from-git'
+
 CLEANFILES = *~
diff --git a/config.cmake.h.in b/config.cmake.h.in
index 91dd6b57..d2c2f204 100644
--- a/config.cmake.h.in
+++ b/config.cmake.h.in
@@ -50,6 +50,15 @@
 /* define to enable use of VSX instructions */
 #cmakedefine FLAC__USE_VSX
 
+/* Define to the commit date of the current git HEAD */
+#cmakedefine GIT_COMMIT_DATE "@GIT_COMMIT_DATE@"
+
+/* Define to the short hash of the current git HEAD */
+#cmakedefine GIT_COMMIT_HASH "@GIT_COMMIT_HASH@"
+
+/* Define to the tag of the current git HEAD */
+#cmakedefine GIT_COMMIT_TAG "@GIT_COMMIT_TAG@"
+
 /* Compiler has the __builtin_bswap16 intrinsic */
 #cmakedefine01 HAVE_BSWAP16
 
diff --git a/configure.ac b/configure.ac
index 7f3bfc20..fafd0bbc 100644
--- a/configure.ac
+++ b/configure.ac
@@ -417,6 +417,12 @@ AC_ARG_ENABLE([examples],
 	AS_HELP_STRING([--disable-examples], [Don't build and install examples]))
 AM_CONDITIONAL([EXAMPLES], [test "x$enable_examples" != "xno"])
 
+dnl Ask git which version FLAC is
+AC_ARG_ENABLE([version-from-git],
+	AS_HELP_STRING([--disable-version-from-git], [Don't use git tag, commit hash and commit date for version number]),
+       [ enable_version_from_git=$enableval ], [ enable_version_from_git=yes ])
+
+
 dnl check for i18n(internationalization); these are from libiconv/gettext
 AM_ICONV
 AM_LANGINFO_CODESET
@@ -540,6 +546,28 @@ dnl for correct FLAC_API
 	CPPFLAGS="-DFLAC__NO_DLL $CPPFLAGS"
 	fi
 
+AC_CHECK_PROG(GIT_FOUND,git,yes)
+
+if test x$GIT_FOUND$enable_version_from_git = "xyesyes"; then
+	GIT_COMMIT_TAG=`git -C $srcdir describe --tags --exact-match 2>/dev/null`
+	GIT_COMMIT_HASH=`git -C $srcdir log -1 --pretty=format:%h 2>/dev/null`
+	GIT_COMMIT_DATE=`git -C $srcdir log -1 --pretty=format:%cd --date=format:%Y%m%d 2>/dev/null`
+	if test ${#GIT_COMMIT_HASH} = 8 && test ${#GIT_COMMIT_DATE} = 8; then
+		GIT_COMMIT_VERSION_AVAIL=yes
+		if test ${#GIT_COMMIT_TAG} != 0 ; then
+			GIT_COMMIT_TAG_AVAIL=yes
+			AC_DEFINE_UNQUOTED(GIT_COMMIT_TAG, "${GIT_COMMIT_TAG}", "Define to the tag of the current git HEAD")
+		else
+			GIT_COMMIT_VERSION_HASH=yes
+		fi
+		AC_DEFINE_UNQUOTED(GIT_COMMIT_HASH, "${GIT_COMMIT_HASH}", "Define to the short hash of the current git HEAD")
+		AC_DEFINE_UNQUOTED(GIT_COMMIT_DATE, "${GIT_COMMIT_DATE}", "Define to the commit date of the current git HEAD")
+	fi
+fi
+
+AC_SUBST(GIT_COMMIT_VERSION_HASH)
+
+
 AC_CONFIG_FILES([ \
 	Makefile \
 	src/Makefile \
@@ -614,6 +642,12 @@ AC_MSG_RESULT([
     Host OS : ................................. ${host_os}
 ])
 
+if test x$GIT_COMMIT_TAG_AVAIL = xyes ; then
+	echo "    Version string : reference libFLAC ${GIT_COMMIT_TAG} ${GIT_COMMIT_DATE}"
+elif test x$GIT_COMMIT_VERSION_AVAIL = xyes ; then
+	echo "    Version string : reference libFLAC git-${GIT_COMMIT_HASH} ${GIT_COMMIT_DATE}"
+fi
+	echo ""
 	echo "    Compiler is GCC : ......................... ${ac_cv_c_compiler_gnu}"
 if test x$ac_cv_c_compiler_gnu = xyes ; then
 	echo "    GCC version : ............................. ${GCC_VERSION}"
diff --git a/src/libFLAC/format.c b/src/libFLAC/format.c
index e5a58bf9..b1939fb5 100644
--- a/src/libFLAC/format.c
+++ b/src/libFLAC/format.c
@@ -44,10 +44,19 @@
 #include "private/format.h"
 #include "private/macros.h"
 
+#if (defined GIT_COMMIT_HASH && defined GIT_COMMIT_DATE)
+# ifdef GIT_COMMIT_TAG
+FLAC_API const char *FLAC__VERSION_STRING = GIT_COMMIT_TAG;
+FLAC_API const char *FLAC__VENDOR_STRING = "reference libFLAC " GIT_COMMIT_TAG " " GIT_COMMIT_DATE;
+# else
+FLAC_API const char *FLAC__VERSION_STRING = "git-" GIT_COMMIT_HASH " " GIT_COMMIT_DATE;
+FLAC_API const char *FLAC__VENDOR_STRING = "reference libFLAC git-" GIT_COMMIT_HASH " " GIT_COMMIT_DATE;
+# endif
+#else
 /* PACKAGE_VERSION should come from configure */
 FLAC_API const char *FLAC__VERSION_STRING = PACKAGE_VERSION;
-
 FLAC_API const char *FLAC__VENDOR_STRING = "reference libFLAC " PACKAGE_VERSION " 20220220";
+#endif
 
 FLAC_API const FLAC__byte FLAC__STREAM_SYNC_STRING[4] = { 'f','L','a','C' };
 FLAC_API const uint32_t FLAC__STREAM_SYNC = 0x664C6143;
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 5935c5d5..6c80f763 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -30,6 +30,10 @@ endif()
 
 set(top_srcdir "${PROJECT_SOURCE_DIR}")
 set(top_builddir "${PROJECT_BINARY_DIR}")
+if(NOT GIT_COMMIT_TAG AND GIT_COMMIT_HASH AND GIT_COMMIT_DATE)
+    set(GIT_COMMIT_VERSION_HASH yes)
+endif()
+
 configure_file(common.sh.in common.sh @ONLY)
 
 set(ALL_TESTS libFLAC grabbag flac metaflac replaygain seeking streams compression)
diff --git a/test/common.sh.in b/test/common.sh.in
index 3184cc30..335f8409 100644
--- a/test/common.sh.in
+++ b/test/common.sh.in
@@ -52,6 +52,7 @@ EXE=@EXEEXT@
 # and build products in the $top_builddir tree.
 top_srcdir=@top_srcdir@
 top_builddir=@top_builddir@
+git_commit_version_hash=@GIT_COMMIT_VERSION_HASH@
 
 # Set `is_win` variable which is used in other scripts that source this one.
 if test $(env | grep -ic '^comspec=') != 0 ; then
diff --git a/test/test_metaflac.sh b/test/test_metaflac.sh
index 3df56a4e..28e4dbf5 100755
--- a/test/test_metaflac.sh
+++ b/test/test_metaflac.sh
@@ -147,7 +147,11 @@ run_metaflac --set-tag="TITLE=He_who_smelt_it_dealt_it" $flacfile
 check_flac
 metaflac_test case06 "--set-tag=TITLE" "--list"
 
-metaflac_test case07 "--show-vendor-tag --show-tag=ARTIST" "--show-vendor-tag --show-tag=ARTIST"
+if [ ! $git_commit_version_hash ] ; then
+	metaflac_test case07 "--show-vendor-tag --show-tag=ARTIST" "--show-vendor-tag --show-tag=ARTIST"
+else
+	echo "test case07 is skipped because version is taken from git"
+fi
 
 run_metaflac --remove-first-tag=ARTIST $flacfile
 check_flac