Don't hand file:// URLs to KGet

Ctrl+S on a page you navigated to directly via file:// is still a
"download" as far as chrome.downloads is concerned, so auto-capture
was intercepting it and handing the local path to KGet, which
rejects it with a confusing "protocol is not supported" dialog since
it's a network download manager, not a file copier. Extend the
existing blob:/data: exclusion to also cover file:/filesystem:, and
apply the same guard to the right-click capture path.

README.md

@@ -83,9 +83,11 @@ git push origin v1.0.0
 
 ## Known limitations
 
-- **`blob:`/`data:` URLs can't be captured.** There's no real network URL to
+- **`blob:`/`data:`/`file:`/`filesystem:` URLs can't be captured.** There's
-  hand to KGet, so these downloads proceed normally through Chrome (a console
+  no real network URL to hand to KGet — this includes saving a page you
-  warning is logged in the extension's service worker).
+  navigated to directly via `file://` (Ctrl+S on it is still a "download" as
+  far as Chrome is concerned) — so these downloads proceed normally through
+  Chrome (a console warning is logged in the extension's service worker).
 - **Auto-capture has a brief head start.** Manifest V3 removed blocking
   `webRequest`, so Chrome begins the download before the extension can cancel
   it. A small/partial temp file may transiently appear before it's erased.

extension/background.js

@@ -11,6 +11,18 @@ async function refreshBadge() {
   updateBadge(autoCaptureEnabled);
 }
 
+// KGet is a network download manager -- it can't "download" a URL that's
+// already local (or embedded in the page), so don't hand it these schemes.
+// file: shows up when saving a page you navigated to directly (Ctrl+S on a
+// file:// URL is still a "download" as far as chrome.downloads is
+// concerned), and KGet's addTransfer rejects it with a confusing
+// "protocol is not supported" dialog if we try.
+const UNSUPPORTED_SCHEMES = ["blob:", "data:", "file:", "filesystem:"];
+
+function isCapturableUrl(url) {
+  return !UNSUPPORTED_SCHEMES.some((scheme) => url.startsWith(scheme));
+}
+
 function sendToKGet(url, filename) {
   chrome.runtime.sendNativeMessage(
     NATIVE_HOST,
@@ -44,6 +56,10 @@ chrome.contextMenus.onClicked.addListener((info) => {
   if (info.menuItemId !== MENU_ID) return;
   const url = info.linkUrl || info.srcUrl;
   if (!url) return;
+  if (!isCapturableUrl(url)) {
+    console.warn("[kget-capture] cannot hand a local/embedded URL to KGet:", url);
+    return;
+  }
   sendToKGet(url, null);
 });
 
@@ -63,8 +79,8 @@ async function captureDownload(item) {
   if (!autoCaptureEnabled) return;
 
   const url = item.finalUrl || item.url;
-  if (url.startsWith("blob:") || url.startsWith("data:")) {
+  if (!isCapturableUrl(url)) {
-    console.warn("[kget-capture] cannot redirect blob:/data: URL, letting Chrome handle it:", url);
+    console.warn("[kget-capture] cannot hand a local/embedded URL to KGet, letting Chrome handle it:", url);
     return;
   }
 

extension/manifest.json

@@ -1,7 +1,7 @@
 {
   "manifest_version": 3,
   "name": "KGet Capture",
-  "version": "1.0.2",
+  "version": "1.0.3",
   "description": "Send browser downloads to KGet (KDE Download Manager) on Linux.",
   "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAtM1nFg5pPd3UBzynUJHj6aUy7bjudZaX9AQTWGMqAX3fXylw1lubSzP1/BaS9ivvgOJg/loyEgzEZlcNPzblFVlg8BqEJ3tntdk2OzYvUs0pUdcPzzyjso9TykCkUUTI7ev8JkreW/FYlinfvNwSYN4/c1s3h8/I6XHtxOdmO1G3bS98+BQaXPldbDmxoKwyWR8u1f8gTO2Mg3GY4BHau3RWf1kgtNzh20p9wE3sEFdWkFu7ArgRCIrWLh6m3O6lolnHQSCWPwtOTx893Qkp9Eu6FwUnoWc8rsYx8sqa0eNCTCS6Kjr1Iu3yEJ5y9390jUiDZTQ/c62ueCTQaYv2bwIDAQAB",
   "permissions": ["downloads", "contextMenus", "storage", "nativeMessaging"],