improved build archive existance verification

reinstall-magisk-on-lineageos

@@ -46,11 +46,14 @@ get_build_url() {
 }
 
 check_exists_latest_lineageos_build() {
-    # The --location lets curl follow the redirection.
-    curl --location "$(get_build_url)?sha256" --output /tmp/lineageos.sha256
-    hash1=$( awk '{print $1}' lineageos.sha256 )
-    hash2=$( sha256sum lineageos.zip | awk '{print $1}' )
-    [[ "$hash1" =~ "$hash2" ]]
+    if [[ -f /tmp/lineageos.zip ]]; then
+        # The --location lets curl follow the redirection.
+        print_message "$(get_build_url)?sha256"
+        curl --location "$(get_build_url)?sha256" --output /tmp/lineageos.sha256
+        hash1=$( awk '{print $1}' /tmp/lineageos.sha256 )
+        hash2=$( sha256sum /tmp/lineageos.zip | awk '{print $1}' )
+        [[ -n $hash1 && -n $hash2 && $hash1 == $hash2 ]]
+    fi
     return
 }
 
@@ -175,10 +178,11 @@ main() {
     is_rooted_debugging_enabled
     print_message "Checking on phone if Magisk is installed"
     check_magisk_app
+    print_message "Checking if build archive already exists"
     if check_exists_latest_lineageos_build; then
-        print_message "Build archive already exists, skipping download"
+        print_message "Build archive found, skipping download"
     else
-        print_message "Downloading build archive from $(get_build_url)"
+        print_message "Build archive not found or hash mismatch, downloading from $(get_build_url)"
         download_latest_lineageos_build
     fi
     print_message "Extracting 'boot.img' from build archive in /tmp/boot.img"