icon-validator: Remove remnants of GSpawn error handling

Now that validate-icon uses execvpe(), status and error were never set,
so rerun_in_sandbox() would have crashed while dereferencing a NULL
error if execvpe() failed. This is reproducible with, for example:

    FLATPAK_BWRAP=/bin/nope flatpak-validate-icon --sandbox 48 48 /path/to/icon

execvpe() does not return on success (the process image is replaced),
and sets errno on failure, so behave accordingly.

Also print the error message to stderr, even if G_MESSAGES_DEBUG is not
set, since it's our only opportunity to indicate to a caller what has
gone wrong.

Signed-off-by: Simon McVittie <smcv@collabora.com>

Closes: #2950
Approved by: alexlarsson

1 files changed, 5 insertions, 16 deletions

diff --git a/icon-validator/validate-icon.c b/icon-validator/validate-icon.c
index 7658f128..9e885070 100644
--- a/icon-validator/validate-icon.c
+++ b/icon-validator/validate-icon.c
@@ -20,6 +20,7 @@
 
 #include <gdk-pixbuf/gdk-pixbuf.h>
 #include <glib/gstdio.h>
+#include <errno.h>
 #include <unistd.h>
 
 static int
@@ -138,9 +139,6 @@ rerun_in_sandbox (const char *arg_width,
   const char * const usrmerged_dirs[] = { "bin", "lib64", "lib", "sbin" };
   int i;
   g_autoptr(GPtrArray) args = g_ptr_array_new_with_free_func (g_free);
-  g_autofree char *err = NULL;
-  int status;
-  g_autoptr(GError) error = NULL;
   char validate_icon[PATH_MAX + 1];
   ssize_t symlink_size;
 
@@ -211,19 +209,10 @@ rerun_in_sandbox (const char *arg_width,
     g_debug ("Icon validation: Spawning %s", cmdline);
   }
 
-  if (execvpe (flatpak_get_bwrap (), (char **) args->pdata, NULL) == -1)
-    {
-      g_debug ("Icon validation: %s", error->message);
-      return 1;
-    }
-
-  if (!g_spawn_check_exit_status (status, NULL))
-    {
-      g_debug ("Icon validation: %s", err);
-      return 1;
-    }
-
-  return 0;
+  execvpe (flatpak_get_bwrap (), (char **) args->pdata, NULL);
+  /* If we get here, then execvpe() failed. */
+  g_printerr ("Icon validation: execvpe %s: %s\n", flatpak_get_bwrap (), g_strerror (errno));
+  return 1;
 }
 
 static gboolean opt_sandbox;