From 654deca933b1acf40c06fe5d6f65103562c5a534 Mon Sep 17 00:00:00 2001
From: sanasol <mail@sanasol.ws>
Date: Tue, 27 Jan 2026 03:38:09 +0100
Subject: [PATCH] Add HYTALE_PATCH_SKIP to skip specific occurrences by index

HYTALE_PATCH_SKIP=0 - skip first occurrence only
HYTALE_PATCH_SKIP=0,2 - skip first and third
HYTALE_PATCH_SKIP=0 HYTALE_PATCH_LIMIT=1 - patch only second occurrence

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
---
 backend/utils/clientPatcher.js | 35 +++++++++++++++++++++++++++-------
 1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/backend/utils/clientPatcher.js b/backend/utils/clientPatcher.js
index 46d8fde..442e478 100644
--- a/backend/utils/clientPatcher.js
+++ b/backend/utils/clientPatcher.js
@@ -185,7 +185,9 @@ class ClientPatcher {
   }
 
   /**
-   * Replace bytes with a limit on number of occurrences (for debugging)
+   * Replace bytes with skip/limit control (for debugging)
+   * HYTALE_PATCH_SKIP: comma-separated indices to skip (e.g., "0,2" skips 1st and 3rd)
+   * HYTALE_PATCH_LIMIT: max number of patches to apply
    */
   replaceBytesLimited(buffer, oldBytes, newBytes, limit) {
     let count = 0;
@@ -196,18 +198,36 @@ class ClientPatcher {
       return { buffer: result, count: 0 };
     }
 
+    // Parse skip list from env
+    const skipIndices = (process.env.HYTALE_PATCH_SKIP || '')
+      .split(',')
+      .filter(s => s.trim())
+      .map(s => parseInt(s.trim(), 10));
+    if (skipIndices.length > 0) {
+      console.log(`    Skip indices: ${skipIndices.join(', ')}`);
+    }
+
     const positions = this.findAllOccurrences(result, oldBytes);
 
-    for (const pos of positions) {
-      if (count >= limit) {
-        console.log(`    Skipping offset 0x${pos.toString(16)} (limit reached)`);
-        continue;
-      }
+    let patchedCount = 0;
+    for (let i = 0; i < positions.length; i++) {
+      const pos = positions[i];
 
       // Log offset and surrounding bytes for debugging
       const before = result.slice(Math.max(0, pos - 8), pos);
       const after = result.slice(pos + oldBytes.length, Math.min(result.length, pos + oldBytes.length + 8));
-      console.log(`    Patching at offset 0x${pos.toString(16)} (${pos})`);
+
+      if (skipIndices.includes(i)) {
+        console.log(`    [${i}] Skipping offset 0x${pos.toString(16)} (in skip list)`);
+        continue;
+      }
+
+      if (patchedCount >= limit) {
+        console.log(`    [${i}] Skipping offset 0x${pos.toString(16)} (limit reached)`);
+        continue;
+      }
+
+      console.log(`    [${i}] Patching at offset 0x${pos.toString(16)} (${pos})`);
       console.log(`      Before: ${before.toString('hex')}`);
       console.log(`      Old pattern: ${oldBytes.slice(0, 20).toString('hex')}${oldBytes.length > 20 ? '...' : ''}`);
       console.log(`      After: ${after.toString('hex')}`);
@@ -216,6 +236,7 @@ class ClientPatcher {
         result.fill(0x00, pos, pos + oldBytes.length);
       }
       newBytes.copy(result, pos);
+      patchedCount++;
       count++;
     }