From d59993abf6c6503ffcc85d151bd59cf9015949c3 Mon Sep 17 00:00:00 2001
From: Elian Doran <contact@eliandoran.me>
Date: Wed, 20 Aug 2025 19:00:41 +0300
Subject: [PATCH] fix(server): potential race condition when rotating logs

---
 apps/server/src/services/log.ts | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/apps/server/src/services/log.ts b/apps/server/src/services/log.ts
index 542b16ad2..3d8cdd6b7 100644
--- a/apps/server/src/services/log.ts
+++ b/apps/server/src/services/log.ts
@@ -12,7 +12,7 @@ if (!fs.existsSync(dataDir.LOG_DIR)) {
     fs.mkdirSync(dataDir.LOG_DIR, 0o700);
 }
 
-let logFile!: fs.WriteStream;
+let logFile: fs.WriteStream | undefined;
 
 const SECOND = 1000;
 const MINUTE = 60 * SECOND;
@@ -107,17 +107,20 @@ function initLogFile() {
     todaysMidnight = getTodaysMidnight();
 
     const logPath = `${dataDir.LOG_DIR}/trilium-${formatDate()}.log`;
+    const isRotating = !!logFile;
 
-    if (logFile) {
-        logFile.end();
+    if (isRotating) {
+        logFile!.end();
+    }
 
-        // Clean up old log files when rotating to a new file
+    logFile = fs.createWriteStream(logPath, { flags: "a" });
+
+    // Clean up old log files when rotating to a new file
+    if (isRotating) {
         cleanupOldLogFiles().catch(() => {
             // Ignore cleanup errors
         });
     }
-
-    logFile = fs.createWriteStream(logPath, { flags: "a" });
 }
 
 function checkDate(millisSinceMidnight: number) {
@@ -141,7 +144,7 @@ function log(str: string | Error) {
 
     millisSinceMidnight = checkDate(millisSinceMidnight);
 
-    logFile.write(`${formatTime(millisSinceMidnight)} ${str}${EOL}`);
+    logFile!.write(`${formatTime(millisSinceMidnight)} ${str}${EOL}`);
 
     console.log(str);
 }