From cc65d91559f9d60fc5e4f449865b81d01795bb67 Mon Sep 17 00:00:00 2001
From: Philip Withnall <pwithnall@gnome.org>
Date: Mon, 21 Jul 2025 12:52:20 +0100
Subject: [PATCH] tests: Add a regression test for GApplication command line
 handling

This will catch regressions like
fc030b2b641a816fbb70e34fbc74d9de150a9384 if they happen again in future,
by testing that fallback argument parsing code path in
`g_application_run()`.

Heavily based on the PyGObject `test_local_and_remote_command_line` unit
test at
https://gitlab.gnome.org/GNOME/pygobject/-/blob/578a55982a76f62719a9d3e345335cfc05013956/tests/test_gio.py#L289.

Thanks to Arjan Molenaar for investigating the failure and writing it
up in !4703.

Signed-off-by: Philip Withnall <pwithnall@gnome.org>
---
 gio/tests/gapplication.c | 71 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 71 insertions(+)

diff --git a/gio/tests/gapplication.c b/gio/tests/gapplication.c
index 001743efb..1d7539219 100644
--- a/gio/tests/gapplication.c
+++ b/gio/tests/gapplication.c
@@ -879,6 +879,76 @@ test_command_line_done (void)
   g_assert_cmpint (status, ==, 42);
 }
 
+typedef GApplication TestCommandLineArgumentsApp;
+typedef GApplicationClass TestCommandLineArgumentsAppClass;
+
+static GType test_command_line_arguments_app_get_type (void);
+G_DEFINE_TYPE (TestCommandLineArgumentsApp, test_command_line_arguments_app, G_TYPE_APPLICATION)
+
+static void
+test_command_line_arguments_app_init (TestCommandLineArgumentsApp *app)
+{
+}
+
+static gboolean
+test_command_line_arguments_app_local_command_line (GApplication   *application,
+                                                    char         ***arguments,
+                                                    int            *exit_status)
+{
+  /* Pretend we couldn’t parse the arguments */
+  return FALSE;
+}
+
+static void
+test_command_line_arguments_app_class_init (TestCommandLineArgumentsAppClass *klass)
+{
+  G_APPLICATION_CLASS (klass)->local_command_line = test_command_line_arguments_app_local_command_line;
+}
+
+static gint
+command_line_arguments_callback (GApplication            *app,
+                                 GApplicationCommandLine *command_line,
+                                 void                    *user_data)
+{
+  char ***out_args = user_data;
+  int argc;
+
+  *out_args = g_application_command_line_get_arguments (command_line, &argc);
+  g_assert_cmpint (argc, ==, g_strv_length (*out_args));
+
+  return 42;  /* exit status */
+}
+
+static void
+test_command_line_arguments (void)
+{
+  g_test_summary ("Test HANDLES_COMMAND_LINE locally with a ->local_command_line "
+                  "vfunc which forces g_application_run() to take a fallback error handling path");
+
+  char *binpath = g_test_build_filename (G_TEST_BUILT, "unimportant", NULL);
+  const char *const argv[] = { binpath, "spam", "eggs", NULL };
+  GApplication *app;
+  int status;
+  unsigned long command_line_id;
+  char **args = NULL;
+
+  app = g_object_new (test_command_line_arguments_app_get_type (),
+                      "application-id", "org.gtk.TestApplication",
+                      "flags", G_APPLICATION_HANDLES_COMMAND_LINE,
+                      NULL);
+  command_line_id = g_signal_connect (app, "command-line", G_CALLBACK (command_line_arguments_callback), &args);
+
+  status = g_application_run (app, G_N_ELEMENTS (argv) - 1, (char **) argv);
+
+  g_assert_cmpint (status, ==, 42);
+  g_assert_cmpstrv (args, argv);
+
+  g_signal_handler_disconnect (app, command_line_id);
+  g_object_unref (app);
+  g_free (binpath);
+  g_strfreev (args);
+}
+
 static void
 test_busy (void)
 {
@@ -1937,6 +2007,7 @@ main (int argc, char **argv)
   g_test_add_func ("/gapplication/resource-path", test_resource_path);
   g_test_add_func ("/gapplication/test-help", test_help);
   g_test_add_func ("/gapplication/command-line-done", test_command_line_done);
+  g_test_add_func ("/gapplication/command-line/arguments", test_command_line_arguments);
   g_test_add_func ("/gapplication/test-busy", test_busy);
   g_test_add_func ("/gapplication/test-handle-local-options1", test_handle_local_options_success);
   g_test_add_func ("/gapplication/test-handle-local-options2", test_handle_local_options_failure);