fix

backend/managers/gameManager.js

@@ -155,7 +155,22 @@ async function updateGameFiles(newVersion, progressCallback, gameDir = GAME_DIR,
   
   try {
     if (progressCallback) {
-      progressCallback('Updating game files...', 0, null, null, null);
+      progressCallback('Backing up user data...', 5, null, null, null);
+    }
+
+    // Backup UserData AVANT de télécharger/installer (critical for same-branch updates)
+    try {
+      console.log(`[UpdateGameFiles] Attempting to backup UserData from old branch: ${oldBranch}`);
+      backupPath = await userDataBackup.backupUserData(installPath, oldBranch, hasVersionConfig);
+      if (backupPath) {
+        console.log(`[UpdateGameFiles] ✓ UserData backed up from ${oldBranch}: ${backupPath}`);
+      }
+    } catch (backupError) {
+      console.warn('[UpdateGameFiles] ✗ UserData backup failed:', backupError.message);
+    }
+
+    if (progressCallback) {
+      progressCallback('Updating game files...', 10, null, null, null);
     }
     console.log(`Updating game files to version: ${newVersion} (branch: ${branch})`);
 
@@ -167,32 +182,17 @@ async function updateGameFiles(newVersion, progressCallback, gameDir = GAME_DIR,
     fs.mkdirSync(tempUpdateDir, { recursive: true });
 
     if (progressCallback) {
-      progressCallback('Downloading new game version...', 10, null, null, null);
+      progressCallback('Downloading new game version...', 20, null, null, null);
     }
 
     const pwrFile = await downloadPWR(branch, newVersion, progressCallback, cacheDir);
 
     if (progressCallback) {
-      progressCallback('Extracting new files...', 50, null, null, null);
+      progressCallback('Extracting new files...', 60, null, null, null);
     }
 
     await applyPWR(pwrFile, progressCallback, tempUpdateDir, toolsDir);
 
-    if (progressCallback) {
-      progressCallback('Backing up user data...', 70, null, null, null);
-    }
-
-    // Backup UserData from OLD branch (before switching)
-    try {
-      console.log(`[UpdateGameFiles] Attempting to backup UserData from old branch: ${oldBranch}`);
-      backupPath = await userDataBackup.backupUserData(installPath, oldBranch, hasVersionConfig);
-      if (backupPath) {
-        console.log(`[UpdateGameFiles] ✓ UserData backed up from ${oldBranch}: ${backupPath}`);
-      }
-    } catch (backupError) {
-      console.warn('[UpdateGameFiles] ✗ UserData backup failed:', backupError.message);
-    }
-
     if (progressCallback) {
       progressCallback('Replacing game files...', 80, null, null, null);
     }

backend/utils/clientPatcher.js

@@ -323,19 +323,19 @@ class ClientPatcher {
     // FORCE PATCHING: Always patch, never skip
     console.log(`Force patching server for ${newDomain}`);
 
-    if (progressCallback) {
-      progressCallback('Preparing to patch server...', 10);
-    }
-
-    console.log('Creating backup...');
-    this.backupClient(serverPath);
-
     if (progressCallback) {
       progressCallback('Extracting server JAR...', 20);
     }
 
     console.log('Opening server JAR...');
-    const zip = new AdmZip(serverPath);
+    let zip;
+    try {
+      zip = new AdmZip(serverPath);
+    } catch (zipError) {
+      console.error('Failed to read server JAR:', zipError.message);
+      return { success: false, error: `Failed to read JAR: ${zipError.message}` };
+    }
+    
     const entries = zip.getEntries();
     console.log(`JAR contains ${entries.length} entries`);
 
@@ -375,7 +375,24 @@ class ClientPatcher {
     }
 
     console.log('Writing patched JAR...');
-    zip.writeZip(serverPath);
+    const tempPath = serverPath + '.patched.tmp';
+    
+    // Write to temp file first to avoid corruption
+    try {
+      zip.writeZip(tempPath);
+      
+      // Replace original with patched version
+      if (fs.existsSync(serverPath)) {
+        fs.unlinkSync(serverPath);
+      }
+      fs.renameSync(tempPath, serverPath);
+    } catch (writeError) {
+      // Cleanup temp file if it exists
+      if (fs.existsSync(tempPath)) {
+        fs.unlinkSync(tempPath);
+      }
+      throw writeError;
+    }
 
     this.markAsPatched(serverPath);