From 8cdec4603ca503b42195eb366299d76995226253 Mon Sep 17 00:00:00 2001
From: Jimmy <jimmy09140456@gmail.com>
Date: Fri, 14 Aug 2026 23:28:31 +0800
Subject: [PATCH] Restore into the path input, not the archive's embedded
 absolute path

Restore only used the path input for a redundant mkdir and then extracted
to / using the absolute path baked into the archive, which pointed at the
stale per-run workspace of whichever run saved it. Extract relative
archives (<basename>/...) into the parent of the requested path; keep a
legacy fallback (extract to /) for old archives, which report cache-hit
only when the requested path actually gains content.
---
 README.md   |  3 +++
 action.yaml | 14 +++++++++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/README.md b/README.md
index e52169b..2c9712d 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,9 @@ A Gitea Action that caches build files as `tar.xz` archives on the runner filesy
 3. Restores by extracting the archive to `/`, saves by creating one
 4. Touches the archive on every hit, so the retention policy can expire by
    last use
+5. Archives store the cached directory **relative** (`<basename>/...`), not its
+   absolute path — a later run restores into its own `path` location, so the
+   cache works across runs even though each run gets a fresh workspace
 
 ## Cache Retention
 
diff --git a/action.yaml b/action.yaml
index 26c9de1..2b36d43 100644
--- a/action.yaml
+++ b/action.yaml
@@ -40,7 +40,19 @@ runs:
         if [ -f "$ARCHIVE" ]; then
           echo "Cache hit: ${CACHE_KEY}"
           mkdir -p "$EXPANDED_PATH"
-          if tar -xf "$ARCHIVE" -C "/" 2>/dev/null; then
+          # New-format archives hold entries relative to the cached directory
+          # (<basename>/...), so extract into the parent of the requested
+          # path. Legacy archives embed the absolute path of the run that
+          # saved them; fall back to extracting them to "/" (status quo,
+          # they are TTL-pruned within the retention window anyway).
+          FIRST_ENTRY=$(tar -tf "$ARCHIVE" 2>/dev/null | head -1)
+          if [ "${FIRST_ENTRY%%/*}" = "$(basename "$EXPANDED_PATH")" ]; then
+            echo "Restoring to: $(dirname "$EXPANDED_PATH")"
+            tar -xf "$ARCHIVE" -C "$(dirname "$EXPANDED_PATH")" 2>/dev/null
+          else
+            tar -xf "$ARCHIVE" -C "/" 2>/dev/null
+          fi
+          if [ -d "$EXPANDED_PATH" ] && [ -n "$(ls -A "$EXPANDED_PATH" 2>/dev/null)" ]; then
             # record last use so the retention policy can expire by access time
             touch "$ARCHIVE"
             echo "cache-hit=true" >> $GITHUB_OUTPUT