file-name-widget: Clarify logic in name_is_valid()

We rely on the presence of an error_message to decide whether the
name is valid.

However, this is misleading, because we can have an invalid name with
no error_message (the empty name case), and we can have a valid name
with an error_message (the dotfile case), requiring 2 early returns.

Instead, use an explicit return variable.

1 files changed, 12 insertions, 5 deletions

diff --git a/src/nautilus-new-folder-dialog-controller.c b/src/nautilus-new-folder-dialog-controller.c
index 14d46a5ec..52b6e217b 100644
--- a/src/nautilus-new-folder-dialog-controller.c
+++ b/src/nautilus-new-folder-dialog-controller.c
@@ -42,30 +42,37 @@ nautilus_new_folder_dialog_controller_name_is_valid (NautilusFileNameWidgetContr
                                                      gchar                             *name,
                                                      gchar                            **error_message)
 {
+    gboolean is_valid;
+
+    is_valid = TRUE;
     if (strlen (name) == 0)
     {
-        return FALSE;
+        is_valid = FALSE;
     }
-
-    if (strstr (name, "/") != NULL)
+    else if (strstr (name, "/") != NULL)
     {
+        is_valid = FALSE;
         *error_message = _("Folder names cannot contain “/”.");
     }
     else if (strcmp (name, ".") == 0)
     {
+        is_valid = FALSE;
         *error_message = _("A folder cannot be called “.”.");
     }
     else if (strcmp (name, "..") == 0)
     {
+        is_valid = FALSE;
         *error_message = _("A folder cannot be called “..”.");
     }
-    else if (g_str_has_prefix (name, "."))
+
+    if (is_valid && g_str_has_prefix (name, "."))
     {
+        /* We must warn about the side effect */
         *error_message = _("Folders with “.” at the beginning of their name are hidden.");
         return TRUE;
     }
 
-    return *error_message == NULL;
+    return is_valid;
 }
 
 static void