Validate exported commands a bit

Avoid obvious nonsense.

common/flatpak-dir.c

@@ -8580,6 +8580,28 @@ flatpak_dir_update_deploy_ref (FlatpakDir *self,
  return TRUE;
 }
 
+static gboolean
+suitable_in_filename (const char *str,
+ GError **error)
+{
+ char *p;
+
+ if (strlen (str) > 80)
+ {
+ g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_FAILED, "Too long");
+ return FALSE;
+ }
+
+ p = strpbrk (str, " \t\n/:");
+ if (p)
+ {
+ g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED, "Contains a bad byte: %c", *p);
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
 gboolean
 flatpak_dir_deploy (FlatpakDir *self,
  const char *origin,
@@ -8969,10 +8991,17 @@ flatpak_dir_deploy (FlatpakDir *self,
  g_autofree char *escaped_cmd = NULL;
  GError *local_error = NULL;
 
+ if (!suitable_in_filename (commands[i], &local_error))
+ {
+ g_warning ("Not exporting command '%s': %s", commands[i], local_error->message);
+ g_error_free (local_error);
+ continue;
+ }
+
  g_set_object (&wrapper, NULL);
  g_clear_pointer (&bin_data, g_free);
 
- filename = g_strconcat (ref_id, "-", commands[i], NULL);
+ filename = g_strconcat (ref_id, "+", commands[i], NULL);
  wrapper = g_file_get_child (bindir, filename);
  escaped_cmd = maybe_quote (commands[i]);