hackage: Also sync timestamp before 01-index

timestamp.json contains hash of snapshot.json.
Related: ustclug/discussions#482

Author: taoky

hackage/sync.sh

@@ -21,7 +21,10 @@ function pull_hackage () {
     # snapshot.json contains hashes of 01-index.tar.gz
     # Download it first to minimize the chance of race condition
     echo "Download snapshot (hashes) ..."
-    $CURL_WRAP -sSL -o snapshot.json.bak "$HACKAGE_BASE_URL/snapshot.json" &> /dev/null
+    snapshot_json=("snapshot.json" "timestamp.json")
+    for json in "${snapshot_json[@]}"; do
+        $CURL_WRAP -sSL -o "$json.bak" "$HACKAGE_BASE_URL/$json" &> /dev/null
+    done
 
     echo "Download latest index ..."
     $CURL_WRAP -sSL -o index.tar.gz "$HACKAGE_BASE_URL/01-index.tar.gz" &> /dev/null
@@ -30,7 +33,7 @@ function pull_hackage () {
     $CURL_WRAP -sSL -o index-00.tar.gz "$HACKAGE_BASE_URL/00-index.tar.gz" &> /dev/null
 
     # download extra json files
-    extra_json=("mirrors.json" "root.json" "timestamp.json")
+    extra_json=("mirrors.json" "root.json")
     for json in "${extra_json[@]}"; do
         $CURL_WRAP -sSL -o "$json" "$HACKAGE_BASE_URL/$json" &> /dev/null
     done
@@ -85,6 +88,7 @@ function pull_hackage () {
     cp index.tar.gz 01-index.tar.gz
     mv index-00.tar.gz 00-index.tar.gz
     mv snapshot.json.bak snapshot.json
+    mv timestamp.json.bak timestamp.json
 }
 
 function download_pkg () {