prefix file path with file://

Former-commit-id: 57ea404aae9bb51e01d11d5036eda82900451424

extension/core/bg/downloads.js

@@ -226,6 +226,12 @@ singlefile.extension.core.bg.downloads = (() => {
 		}
 		const downloadData = await download(downloadInfo, options.filenameReplacementCharacter);
 		if (downloadData.filename && pageData.bookmarkId && pageData.replaceBookmarkURL) {
+			if (!downloadData.filename.startsWith("file:")) {
+				if (downloadData.filename.startsWith("/")) {
+					downloadData.filename = downloadData.filename.substring(1);
+				}
+				downloadData.filename = "file:///" + downloadData.filename;
+			}
 			await singlefile.extension.core.bg.bookmarks.update(pageData.bookmarkId, { url: downloadData.filename });
 		}
 	}