Fix right-click download landing in home folder with wrong filename

Route context-menu captures through chrome.downloads so they resolve
Chrome's real filename (Content-Disposition, extension, etc.) via the
same onDeterminingFilename path auto-capture already uses, and harden
the native host against the bare-directory destDir KGet was misparsing
as a filename.

README.md

@@ -97,13 +97,6 @@ git push origin v1.0.0
   only skips its interactive "New Download" dialog when given a real
   destination path up front, so instant capture and an editable prompt are
   mutually exclusive given KGet's D-Bus API.
-- **The context-menu capture can't always get the correct filename.**
-  Auto-capture gets the real filename for free from Chrome's own
-  `Content-Disposition` resolution. Right-click captures don't have that —
-  the extension only has the raw URL — so KGet falls back to guessing from
-  the URL path, which is wrong for opaque/signed URLs (e.g. cloud storage
-  links). Fixing this would require broad host permissions and an extra HTTP
-  request per right-click, which isn't worth it for now.
 - **Chrome may still show its own "Save As" dialog** if you skipped step 5 of
   Install above — see there for why and how to fix it.
 - **KGet must already be running.** If it's not, captures fail silently from

extension/background.js

@@ -52,6 +52,11 @@ chrome.runtime.onInstalled.addListener(async (details) => {
   refreshBadge();
 });
 
+// Downloads started from the context menu, tracked so captureDownload()
+// still resolves/forwards their real filename even when auto-capture is
+// toggled off -- a right-click "Download with KGet" should always work.
+const pendingContextMenuDownloads = new Set();
+
 chrome.contextMenus.onClicked.addListener((info) => {
   if (info.menuItemId !== MENU_ID) return;
   const url = info.linkUrl || info.srcUrl;
@@ -60,7 +65,22 @@ chrome.contextMenus.onClicked.addListener((info) => {
     console.warn("[kget-capture] cannot hand a local/embedded URL to KGet:", url);
     return;
   }
-  sendToKGet(url, null);
+  // Route through chrome.downloads instead of sending the raw URL straight
+  // to KGet -- this reuses onDeterminingFilename/captureDownload below to
+  // get Chrome's real resolved filename (Content-Disposition, etc.) instead
+  // of leaving KGet to guess one from the bare URL, which drops query
+  // strings and gets opaque/signed URLs wrong.
+  chrome.downloads.download({ url }, (downloadId) => {
+    if (chrome.runtime.lastError || downloadId === undefined) {
+      console.error(
+        "[kget-capture] couldn't start download to resolve filename, falling back to raw URL:",
+        chrome.runtime.lastError && chrome.runtime.lastError.message
+      );
+      sendToKGet(url, null);
+      return;
+    }
+    pendingContextMenuDownloads.add(downloadId);
+  });
 });
 
 // onDeterminingFilename (rather than onCreated) fires once Chrome has
@@ -75,8 +95,9 @@ chrome.downloads.onDeterminingFilename.addListener((item, suggest) => {
 });
 
 async function captureDownload(item) {
+  const isContextMenuCapture = pendingContextMenuDownloads.delete(item.id);
   const { autoCaptureEnabled } = await chrome.storage.local.get({ autoCaptureEnabled: true });
-  if (!autoCaptureEnabled) return;
+  if (!autoCaptureEnabled && !isContextMenuCapture) return;
 
   const url = item.finalUrl || item.url;
   if (!isCapturableUrl(url)) {

native-host/kget_capture_host.py

@@ -49,7 +49,12 @@ def add_transfer(url, filename):
     # sidesteps KGet's own filename guess, which is derived purely from the
     # URL path and gets it wrong for opaque/signed URLs.
     dest_dir = default_download_dir()
-    dest = os.path.join(dest_dir, filename) if filename else dest_dir
+    # A bare directory path with no trailing slash (e.g. "/home/ian/Downloads")
+    # gets misparsed by KGet's addTransfer as dir="/home/ian" + filename=
+    # "Downloads" -- the same split it applies to a real dir/filename path --
+    # landing the transfer in the parent directory instead. A trailing slash
+    # keeps it unambiguous when we don't have a real filename to append.
+    dest = os.path.join(dest_dir, filename) if filename else dest_dir.rstrip("/") + "/"
     cmd = [
         "dbus-send",
         "--print-reply",