Ensure .deb compression

Makefile

@@ -220,6 +220,7 @@ push: # I=<image> : Push Riju image to Docker registry
 
 upload: # L=<lang> T=<type> : Upload .deb to S3
 	@: $${L} $${T} $${S3_BUCKET}
+	tools/ensure-deb-compressed.bash
 	aws s3 rm --recursive $(S3_HASH)
 	aws s3 cp $(BUILD)/$(DEB) $(S3_DEB)
 	hash="$$(dpkg-deb -f $(BUILD)/$(DEB) Riju-Script-Hash | grep .)"; aws s3 cp - "$(S3_HASH)/$${hash}" < /dev/null

tools/ensure-deb-compressed.bash

@@ -0,0 +1,76 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+: ${L} ${T}
+
+deb="build/${T}/${L}/riju-${T}-${L}.deb"
+tmp="build/${T}/${L}/ar-tmp"
+
+rm -rf "${tmp}"
+
+files="$(ar t "${deb}" | grep -F .tar | grep -Fv .xz || true)"
+
+if [[ -z "${files}" ]]; then
+    exit 0
+fi
+
+du -sh "${deb}"
+
+echo >&2 "found files in ${deb} needing recompression:"
+echo "${files}" | sed >&2 's/^/  /'
+
+echo >&2 "extracting ${deb} to ${tmp}..."
+mkdir -p "${tmp}"
+ar xv "${deb}" --output "${tmp}" | sed >&2 's/^/  /'
+
+echo >&2 "recompressing extracted files..."
+
+processed_files=()
+while read file; do
+    if echo "${file}" | grep -F .tar | grep -Fvq .xz; then
+        ext="$(echo "${file}" | sed -E 's/^.+\.tar//')"
+        case "${ext}" in
+            "")
+                echo >&2 "  ${file} => ${file}.xz"
+                xz "${tmp}/${file}"
+                processed_files=("${processed_files[@]}" "${file}.xz")
+                ;;
+            ".gz")
+                echo >&2 "  ${file} => ${file%.gz}.xz"
+                gunzip "${tmp}/${file}" -c | xz - > "${tmp}/${file%.gz}"
+                rm "${tmp}/${file}"
+                processed_files=("${processed_files[@]}" "${file%.gz}")
+                ;;
+            *)
+                echo >&2 "  !! unknown file extension in ${file}"
+                exit 1
+                ;;
+        esac
+    else
+        processed_files=("${processed_files[@]}" "${file}")
+    fi
+done < <(ar t "${deb}")
+
+# NB we need to keep track of the processed_files array because the
+# order needs to be preserved, surprisingly enough:
+# https://ubuntuforums.org/archive/index.php/t-1481153.html
+
+echo >&2 "recreating archive at ${deb}.tmp..."
+pushd "${tmp}" >/dev/null
+ar rcv "../$(basename "${deb}").tmp" "${processed_files[@]}" | sed 's/^/  /'
+popd >/dev/null
+
+echo >&2 "cleaning up ${tmp}..."
+rm -rf "${tmp}"
+
+echo >&2 "renaming ${deb}.tmp => ${deb}..."
+mv "${deb}.tmp" "${deb}"
+
+files="$(ar t "${deb}" | grep -F .tar | grep -Fv .xz || true)"
+
+if [[ -n "${files}" ]]; then
+    echo >&2 "error: still found files in ${deb} needing recompression:"
+    echo "${files}" | sed >&2 's/^/  /'
+    exit 1
+fi