1 files changed, 28 insertions, 0 deletions
diff --git a/fetch-forge b/fetch-forge
new file mode 100755
index 0000000..1a3aa99
--- /dev/null
+++ b/fetch-forge
@@ -0,0 +1,28 @@
+#!/bin/sh
+# Vendor git-forge's source into forge/ for the image build. Derived state:
+# gitignored, and running this again replaces it.
+#
+#	GIT_FORGE_SRC	where to take it from, default ../git-forge
+#	GIT_FORGE_REV	which commit, default the one in forge.rev
+set -eu
+
+src="${GIT_FORGE_SRC:-../git-forge}"
+rev="${GIT_FORGE_REV:-$(cat forge.rev)}"
+
+# Resolved before anything is removed, so a revision that is not there fails
+# with the tree that was vendored last still in place. --verify, because plain
+# rev-parse echoes a forty character sha back without looking for it.
+sha=$(git -C "$src" rev-parse --verify "$rev^{commit}")
+
+# Into a file rather than a pipe: a pipeline exits with the status of its last
+# command, so a failed archive would be an empty forge/ and an exit of zero.
+archive=$(mktemp)
+trap 'rm -f "$archive"' EXIT
+git -C "$src" archive -o "$archive" "$sha"
+
+rm -rf forge
+mkdir forge
+tar -xf "$archive" -C forge
+echo "$sha" >forge/.rev
+
+echo "vendored git-forge $sha from $src"