Merge branch '3768-test-trap-subprocess-flags' into 'main'

gtestutils: Fix G_TEST_SUBPROCESS_INHERIT_STDIN in g_test_trap_subprocess()

Closes #3768

See merge request GNOME/glib!4757

glib/gtestutils.c

@@ -4177,7 +4177,7 @@ g_test_trap_subprocess_with_envp (const char           *test_path,
   flags = G_SPAWN_DO_NOT_REAP_CHILD;
   if (test_log_fd != -1)
     flags |= G_SPAWN_LEAVE_DESCRIPTORS_OPEN;
-  if (test_flags & G_TEST_TRAP_INHERIT_STDIN)
+  if (test_flags & G_TEST_SUBPROCESS_INHERIT_STDIN)
     flags |= G_SPAWN_CHILD_INHERITS_STDIN;
 
   if (!g_spawn_async_with_pipes (test_initial_cwd,

glib/tests/testing.c

@@ -35,6 +35,13 @@
 #include <stdlib.h>
 #include <string.h>
 
+#ifdef G_OS_UNIX
+#define _POSIX_C_SOURCE 200809L  /* for F_DUPFD_CLOEXEC */
+#include <fcntl.h>
+#include <glib-unix.h>
+#include <unistd.h>
+#endif
+
 #define TAP_VERSION G_STRINGIFY (14)
 #define TAP_SUBTEST_PREFIX "    "
 
@@ -423,6 +430,56 @@ test_subprocess_envp (void)
   g_strfreev (envp);
 }
 
+static void
+test_subprocess_stdin (void)
+{
+#ifdef G_OS_UNIX
+  int old_stdin_fd = -1;
+  int pipe_fd[2] = { -1, -1 };
+  const char *test_string = "*hello there*";
+  GError *local_error = NULL;
+
+  if (g_test_subprocess ())
+    {
+      char buf[100];
+      ssize_t n_read;
+
+      g_assert_no_errno (n_read = read (STDIN_FILENO, buf, sizeof (buf)));
+      g_assert_cmpint (n_read, >, 0);
+
+      g_print ("Read: %.*s\n", (int) n_read, buf);
+
+      return;
+    }
+
+  /* Temporarily override this process’ stdin with a pipe. */
+  old_stdin_fd = fcntl (STDIN_FILENO, F_DUPFD_CLOEXEC, 0);
+  g_assert_cmpint (old_stdin_fd, >=, 0);
+
+  g_unix_open_pipe (pipe_fd, O_CLOEXEC, &local_error);
+  g_assert_no_error (local_error);
+
+  g_assert_no_errno (dup2 (pipe_fd[0], STDIN_FILENO));
+
+  /* Write something into it for the subprocess to read. */
+  g_assert_no_errno (write (pipe_fd[1], test_string, strlen (test_string) + 1));
+
+  /* Run the subprocess. */
+  g_test_trap_subprocess (NULL, 0, G_TEST_SUBPROCESS_INHERIT_STDIN);
+  g_test_trap_assert_passed ();
+  g_test_trap_assert_stdout (test_string);
+
+  /* Restore the old stdin */
+  g_assert_no_errno (dup2 (old_stdin_fd, STDIN_FILENO));
+
+  g_assert_no_errno (close (old_stdin_fd));
+  g_assert_no_errno (close (pipe_fd[0]));
+  g_assert_no_errno (close (pipe_fd[1]));
+#else
+  g_test_skip ("Testing stdin for subprocesses can only be done on Unix at the moment");
+#endif
+}
+
 /* run a test with fixture setup and teardown */
 typedef struct {
   guint  seed;
@@ -2916,6 +2973,7 @@ main (int   argc,
   g_test_add_func ("/trap_subprocess/no-such-test", test_subprocess_no_such_test);
   g_test_add_func ("/trap_subprocess/timeout", test_subprocess_timeout);
   g_test_add_func ("/trap_subprocess/envp", test_subprocess_envp);
+  g_test_add_func ("/trap_subprocess/stdin", test_subprocess_stdin);
 
   g_test_add_func ("/trap_subprocess/patterns", test_subprocess_patterns);