From 4b1aa9908fe25b919a14602bf982e0c6e4ead64a Mon Sep 17 00:00:00 2001
From: Sergii Pylypenko <x.pelya.x@gmail.com>
Date: Thu, 5 Dec 2024 15:44:57 +0200
Subject: [PATCH] Use an absolute filename for the file save dialog on Linux

This fixes #6912.
On Gnome the save dialog works with any filename, on KDE Plasma
the save dialog opens with an empty filename input field,
unless the application uses an absolute file path instead of only the filename.
This commit will use the ~/Downloads directory as the default path,
which seems like a better choice then dumping files into the user's home dir.
---
 app/main.ts | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/app/main.ts b/app/main.ts
index 22bca044a0..b1ff3f829a 100644
--- a/app/main.ts
+++ b/app/main.ts
@@ -5,6 +5,8 @@ import { join, normalize, extname, dirname, basename } from 'path';
 import { pathToFileURL } from 'url';
 import * as os from 'os';
 import { chmod, realpath, writeFile } from 'fs-extra';
+import { exec } from 'child_process';
+import { promisify } from 'util';
 import { randomBytes } from 'crypto';
 import { createParser } from 'dashdash';
 
@@ -3021,6 +3023,25 @@ ipc.handle('show-save-dialog', async (_event, { defaultPath }) => {
     return { canceled: true };
   }
 
+  if (process.platform === 'linux' && defaultPath && defaultPath.charAt(0) !== '/') {
+    // On Linux the defaultPath should be an absolute path, otherwise the save dialog will have an empty filename on KDE/Plasma
+    let downloadsPath = '';
+    try {
+      downloadsPath = (await promisify(exec)('xdg-user-dir DOWNLOAD')).stdout.trim();
+      getLogger().info('show-save-dialog: saving to user downloads directory: ' + downloadsPath);
+    } catch (e) {
+      // If we cannot get Downloads path, fall back to the user's home directory
+      try {
+        downloadsPath = process.env['HOME'];
+        getLogger().info('show-save-dialog: saving to user home directory: ' + downloadsPath);
+      } catch (ee) {
+      }
+    }
+    if (downloadsPath) {
+      defaultPath = downloadsPath + '/' + defaultPath;
+    }
+  }
+
   const { canceled, filePath: selectedFilePath } = await dialog.showSaveDialog(
     mainWindow,
     {