From 818a746a88dc9489620f0bc38af5d3cc2ffe12b3 Mon Sep 17 00:00:00 2001
From: Amit Haridas <amit.wh@gmail.com>
Date: Sat, 11 Oct 2025 13:46:48 +0530
Subject: [PATCH] =?UTF-8?q?Fix=20double-click=20file=20opening=20in=20inst?=
 =?UTF-8?q?alled=20Windows=20app=20(v1.7.5)=20This=20fix=20addresses=20the?=
 =?UTF-8?q?=20critical=20issue=20where=20double-clicking=20.md=20files=20w?=
 =?UTF-8?q?ould=20not=20open=20them=20in=20the=20installed=20PanConverter?=
 =?UTF-8?q?=20application=20on=20Windows.=20##=20Root=20Cause=20When=20a?=
 =?UTF-8?q?=20user=20double-clicks=20a=20file=20and=20the=20app=20is=20alr?=
 =?UTF-8?q?eady=20running,=20Windows=20tries=20to=20launch=20a=20SECOND=20?=
 =?UTF-8?q?INSTANCE=20with=20the=20file=20path.=20Without=20single-instanc?=
 =?UTF-8?q?e=20lock=20handling,=20that=20second=20instance=20would=20exit?=
 =?UTF-8?q?=20and=20the=20first=20instance=20would=20never=20receive=20the?=
 =?UTF-8?q?=20file=20path.=20##=20Changes=20-=20Added=20single-instance=20?=
 =?UTF-8?q?lock=20handling=20in=20main.js=20(lines=2052-85)=20-=20Implemen?=
 =?UTF-8?q?ted=20second-instance=20event=20handler=20to=20capture=20file?=
 =?UTF-8?q?=20paths=20-=20Focus=20existing=20window=20when=20second=20inst?=
 =?UTF-8?q?ance=20is=20attempted=20-=20Pass=20file=20path=20to=20existing?=
 =?UTF-8?q?=20instance=20using=20openFileFromPath()=20-=20Properly=20handl?=
 =?UTF-8?q?e=20rendererReady=20state=20for=20file=20opening=20##=20Testing?=
 =?UTF-8?q?=20-=20Works=20in=20development=20mode=20(npm=20start)=20-=20Sh?=
 =?UTF-8?q?ould=20now=20work=20correctly=20in=20installed=20Windows=20app?=
 =?UTF-8?q?=20with=20double-click=20-=20Maintains=20single=20instance=20be?=
 =?UTF-8?q?havior=20across=20all=20file=20opening=20methods=20=F0=9F=A4=96?=
 =?UTF-8?q?=20Generated=20with=20[Claude=20Code](https://claude.com/claude?=
 =?UTF-8?q?-code)?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 package.json |  2 +-
 src/main.js  | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/package.json b/package.json
index 93eb969..38d2093 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "pan-converter",
-  "version": "1.7.4",
+  "version": "1.7.5",
   "description": "Cross-platform Markdown editor and converter using Pandoc",
   "main": "src/main.js",
   "scripts": {
diff --git a/src/main.js b/src/main.js
index e2e0981..db1aad3 100644
--- a/src/main.js
+++ b/src/main.js
@@ -49,6 +49,41 @@ let currentFile = null; // This will now represent the active tab's file
 let pandocAvailable = null; // Cache pandoc availability check
 let rendererReady = false; // Track if renderer is ready to receive file data
 
+// Handle single instance lock for Windows file association
+// When a file is double-clicked and the app is already running,
+// Windows tries to start a second instance. We prevent this and
+// pass the file to the existing instance instead.
+const gotTheLock = app.requestSingleInstanceLock();
+
+if (!gotTheLock) {
+  // Another instance is already running, quit this one
+  app.quit();
+} else {
+  // This is the first instance, handle second-instance events
+  app.on('second-instance', (event, commandLine, workingDirectory) => {
+    // Someone tried to run a second instance, focus our window instead
+    if (mainWindow) {
+      if (mainWindow.isMinimized()) mainWindow.restore();
+      mainWindow.focus();
+    }
+
+    // Check if a file was passed to the second instance
+    // commandLine is an array like: ['electron.exe', 'app.asar', 'file.md']
+    const fileArgs = commandLine.slice(2);
+    for (const arg of fileArgs) {
+      if ((arg.endsWith('.md') || arg.endsWith('.markdown')) && fs.existsSync(arg)) {
+        // Open the file in the existing instance
+        if (rendererReady) {
+          openFileFromPath(arg);
+        } else {
+          app.pendingFile = arg;
+        }
+        break;
+      }
+    }
+  });
+}
+
 // Check if pandoc is available
 function checkPandocAvailability() {
   return new Promise((resolve) => {