Missing saveAs csv file type in file saveAs dialog (fix #96283)

src/vs/workbench/services/dialogs/browser/abstractFileDialogService.ts

@@ -279,21 +279,25 @@ export abstract class AbstractFileDialogService implements IFileDialogService {
 			return filter;
 		}));
 
-		// Filters are a bit weird on Windows, based on having a match or not:
-		// Match: we put the matching filter first so that it shows up selected and the all files last
-		// No match: we put the all files filter first
-		const allFilesFilter = { name: nls.localize('allFiles', "All Files"), extensions: ['*'] };
-		if (matchingFilter) {
-			filters.unshift(matchingFilter);
-			filters.unshift(allFilesFilter);
-		} else {
-			filters.unshift(allFilesFilter);
+		// We have no matching filter, e.g. because the language
+		// is unknown. We still add the extension to the list of
+		// filters though so that it can be picked
+		// (https://github.com/microsoft/vscode/issues/96283)
+		if (!matchingFilter && ext) {
+			matchingFilter = { name: nls.localize('fileExt', "{0} File", ext), extensions: [trim(ext, '.')] };
 		}
 
-		// Allow to save file without extension
-		filters.push({ name: nls.localize('noExt', "No Extension"), extensions: [''] });
-
-		options.filters = filters;
+		// Order of filters is
+		// - File Extension Match
+		// - All Files
+		// - All Languages
+		// - No Extension
+		options.filters = coalesce([
+			matchingFilter,
+			{ name: nls.localize('allFiles', "All Files"), extensions: ['*'] },
+			...filters,
+			{ name: nls.localize('noExt', "No Extension"), extensions: [''] }
+		]);
 
 		return options;
 	}