[gnome-builder] fusermount: simplify fusermount wrapper to use flatpak-spawn

[Christian Hergert <chergert src gnome org>]

commit 016a15a24443afb2550bc93e5b6baf1fb77016c6
Author: Christian Hergert <chergert redhat com>
Date:   Mon Feb 11 22:20:43 2019 -0800

    fusermount: simplify fusermount wrapper to use flatpak-spawn
    
    This reduces the amount of code going on here and helps reduce the chances
    of error by reusing flatpak-spawn.

 src/fusermount-wrapper.c | 137 +++++++++++++++++++----------------------------
 src/meson.build          |   2 +-
 2 files changed, 57 insertions(+), 82 deletions(-)
---
diff --git a/src/fusermount-wrapper.c b/src/fusermount-wrapper.c
index 13a23af1c..3b3f35a12 100644
--- a/src/fusermount-wrapper.c
+++ b/src/fusermount-wrapper.c
@@ -18,23 +18,24 @@
  * SPDX-License-Identifier: GPL-3.0-or-later
  */
 
-#include "config.h"
-
 #include <errno.h>
-#include <libide-threading.h>
-#include <stdlib.h>
-#include <unistd.h>
-
-static gint exit_code;
+#include <glib.h>
+#include <sys/prctl.h>
+#include <signal.h>
 
 static gboolean
 parse_fd (const gchar *str,
           gint        *fd)
 {
-  gint64 v = g_ascii_strtoll (str, NULL, 10);
+  gint64 v;
 
   *fd = -1;
 
+  if (str == NULL)
+    return FALSE;
+
+  v = g_ascii_strtoll (str, NULL, 10);
+
   if (v < 0 || v > G_MAXINT)
     return FALSE;
 
@@ -47,82 +48,56 @@ parse_fd (const gchar *str,
 }
 
 static void
-wait_cb (IdeSubprocess *subprocess,
-         GAsyncResult  *result,
-         GMainLoop     *main_loop)
-{
-  g_autoptr(GError) error = NULL;
-
-  g_assert (IDE_IS_SUBPROCESS (subprocess));
-  g_assert (G_IS_ASYNC_RESULT (result));
-
-  if (!ide_subprocess_wait_finish (subprocess, result, &error))
-    g_error ("Subprocess wait failed: %s", error->message);
-
-  if (ide_subprocess_get_if_signaled (subprocess))
-    kill (getpid (), ide_subprocess_get_term_sig (subprocess));
-  else
-    exit (ide_subprocess_get_exit_status (subprocess));
-
-  g_main_loop_quit (main_loop);
-}
-
-static void
-log_func (const gchar    *log_domain,
-          GLogLevelFlags  log_level,
-          const gchar    *message,
-          gpointer        user_data)
+child_setup_func (gpointer data)
 {
-  if (log_level & G_LOG_FLAG_FATAL)
-    g_printerr ("%s\n", message);
+  prctl (PR_SET_PDEATHSIG, SIGKILL);
 }
 
-int
-main (int   argc,
-      char *argv[])
+gint
+main (gint   argc,
+      gchar *argv[])
 {
-  g_autoptr(IdeSubprocessLauncher) launcher = NULL;
-  g_autoptr(GDBusConnection) bus = NULL;
-  g_autoptr(IdeSubprocess) subprocess = NULL;
-  g_autoptr(GMainLoop) main_loop = NULL;
-  g_autoptr(GError) error = NULL;
-  const gchar *env;
-  gint fd = -1;
-
-  g_log_set_default_handler (log_func, NULL);
-
-  main_loop = g_main_loop_new (NULL, FALSE);
-
-  if (!(bus = g_bus_get_sync (G_BUS_TYPE_SESSION, NULL, &error)))
-    g_error ("Failed to connect to session bus: %s", error->message);
-
-  launcher = ide_subprocess_launcher_new (0);
-
-  ide_subprocess_launcher_push_argv (launcher, "fusermount");
+  g_autoptr(GPtrArray) new_argv = NULL;
+  g_autofree gchar *path = NULL;
+  g_autofree gchar *env_param = NULL;
+  g_autofree gchar *fwd_param = NULL;
+  const gchar *fuse_commfd_env;
+  gint fuse_commfd = -1;
+  gint exit_status;
+
+  fuse_commfd_env = g_getenv ("_FUSE_COMMFD");
+
+  if (!parse_fd (fuse_commfd_env, &fuse_commfd))
+    return EXIT_FAILURE;
+
+  env_param = g_strdup_printf ("--env=_FUSE_COMMFD=%s", fuse_commfd_env);
+  fwd_param = g_strdup_printf ("--forward-fd=%d", fuse_commfd);
+
+  if (!(path = g_find_program_in_path ("flatpak-spawn")))
+    return EXIT_FAILURE;
+
+  new_argv = g_ptr_array_new ();
+  g_ptr_array_add (new_argv, path);
+  g_ptr_array_add (new_argv, (gchar *)"--clear-env");
+  g_ptr_array_add (new_argv, (gchar *)"--watch-bus");
+  g_ptr_array_add (new_argv, (gchar *)"--host");
+  g_ptr_array_add (new_argv, env_param);
+  g_ptr_array_add (new_argv, fwd_param);
+  g_ptr_array_add (new_argv, (gchar *)"fusermount");
   for (guint i = 1; i < argc; i++)
-    ide_subprocess_launcher_push_argv (launcher, argv[i]);
-
-  ide_subprocess_launcher_set_cwd (launcher, g_get_current_dir ());
-  ide_subprocess_launcher_set_run_on_host (launcher, TRUE);
-  ide_subprocess_launcher_take_stdin_fd (launcher, dup (STDIN_FILENO));
-  ide_subprocess_launcher_take_stdout_fd (launcher, dup (STDOUT_FILENO));
-  ide_subprocess_launcher_take_stderr_fd (launcher, dup (STDERR_FILENO));
-
-  if ((env = g_getenv ("_FUSE_COMMFD")) && parse_fd (env, &fd) && fd > 2)
-    {
-      ide_subprocess_launcher_setenv (launcher, "_FUSE_COMMFD", env, TRUE);
-      ide_subprocess_launcher_take_fd (launcher, fd, fd);
-    }
-
-  if (!(subprocess = ide_subprocess_launcher_spawn (launcher, NULL, &error)))
-    g_error ("ERROR: %s", error->message);
-
-  ide_subprocess_wait_async (subprocess,
-                             NULL,
-                             (GAsyncReadyCallback)wait_cb,
-                             main_loop);
-
-  g_main_loop_run (main_loop);
-
-  return exit_code;
+    g_ptr_array_add (new_argv, argv[i]);
+  g_ptr_array_add (new_argv, NULL);
+
+  g_spawn_sync (NULL,
+                (gchar **)new_argv->pdata,
+                NULL,
+                (G_SPAWN_LEAVE_DESCRIPTORS_OPEN | G_SPAWN_CHILD_INHERITS_STDIN),
+                child_setup_func,
+                NULL,
+                NULL,
+                NULL,
+                &exit_status,
+                NULL);
+
+  return exit_status;
 }
diff --git a/src/meson.build b/src/meson.build
index 597595467..3d4b5bfcb 100644
--- a/src/meson.build
+++ b/src/meson.build
@@ -57,7 +57,7 @@ if get_option('fusermount_wrapper')
               c_args: exe_c_args + release_args,
            link_args: exe_link_args,
        install_rpath: pkglibdir_abs,
-        dependencies: [libide_core_deps, libide_io_dep, libide_threading_dep],
+        dependencies: [libglib_dep],
   )
 
 endif