1 files changed, 94 insertions, 0 deletions
diff --git a/git-gui/GIT-VERSION-GEN b/git-gui/GIT-VERSION-GEN
new file mode 100755
index 0000000000..c2767b4136
--- /dev/null
+++ b/git-gui/GIT-VERSION-GEN
@@ -0,0 +1,94 @@
+#!/bin/sh
+
+DEF_VER=0.21.GITGUI
+
+LF='
+'
+
+if test "$#" -ne 2
+then
+	echo >&2 "usage: $0 <SOURCE_DIR> <OUTPUT>"
+	exit 1
+fi
+
+SOURCE_DIR="$1"
+OUTPUT="$2"
+
+# Protect us from reading Git version information outside of the Git directory
+# in case it is not a repository itself, but embedded in an unrelated
+# repository.
+GIT_CEILING_DIRECTORIES="$SOURCE_DIR/.."
+export GIT_CEILING_DIRECTORIES
+
+tree_search ()
+{
+	head=$1
+	tree=$2
+	for p in $(git -C "$SOURCE_DIR" rev-list --parents --max-count=1 $head 2>/dev/null)
+	do
+		test $tree = $(git -C "$SOURCE_DIR" rev-parse $p^{tree} 2>/dev/null) &&
+		vn=$(git -C "$SOURCE_DIR" describe --abbrev=4 $p 2>/dev/null) &&
+		case "$vn" in
+		gitgui-[0-9]*) echo $vn; break;;
+		esac
+	done
+}
+
+# Always use the tarball version file if found, just
+# in case we are somehow contained in a larger git
+# repository that doesn't actually track our state.
+# (At least one package manager is doing this.)
+#
+# We may be a subproject, so try looking for the merge
+# commit that supplied this directory content if we are
+# not at the toplevel.  We probably will always be the
+# second parent in the commit, but we shouldn't rely on
+# that fact.
+#
+# If we are at the toplevel or the merge assumption fails
+# try looking for a gitgui-* tag.
+
+if test -f "$SOURCE_DIR"/version &&
+   VN=$(cat "$SOURCE_DIR"/version)
+then
+	: happy
+elif prefix="$(git -C "$SOURCE_DIR" rev-parse --show-prefix 2>/dev/null)"
+   test -n "$prefix" &&
+   head=$(git -C "$SOURCE_DIR" rev-list --max-count=1 HEAD -- . 2>/dev/null) &&
+   tree=$(git -C "$SOURCE_DIR" rev-parse --verify "HEAD:$prefix" 2>/dev/null) &&
+   VN=$(tree_search $head $tree)
+   case "$VN" in
+   gitgui-[0-9]*) : happy ;;
+   *) (exit 1) ;;
+   esac
+then
+	VN=$(echo "$VN" | sed -e 's/^gitgui-//;s/-/./g');
+elif VN=$(git -C "$SOURCE_DIR" describe --abbrev=4 HEAD 2>/dev/null) &&
+   case "$VN" in
+   gitgui-[0-9]*) : happy ;;
+   *) (exit 1) ;;
+   esac
+then
+	VN=$(echo "$VN" | sed -e 's/^gitgui-//;s/-/./g');
+else
+	VN="$DEF_VER"
+fi
+
+dirty=$(git -C "$SOURCE_DIR" diff-index --name-only HEAD 2>/dev/null) || dirty=
+case "$dirty" in
+'')
+	;;
+*)
+	VN="$VN-dirty" ;;
+esac
+
+if test -r "$OUTPUT"
+then
+	VC=$(sed -e 's/^GITGUI_VERSION=//' <"$OUTPUT")
+else
+	VC=unset
+fi
+test "$VN" = "$VC" || {
+	echo >&2 "GITGUI_VERSION=$VN"
+	echo "GITGUI_VERSION=$VN" >"$OUTPUT"
+}