[gtk/wip/otte/undo: 10/17] entry: Allow entry to decide to not record undo actions

[Benjamin Otte <otte src gnome org>]

commit d39f484161b90ecf2f0f75c3bb397298ca0044ae
Author: Benjamin Otte <otte redhat com>
Date:   Sun Aug 16 07:41:27 2015 +0200

    entry: Allow entry to decide to not record undo actions
    
    This is useful when recording would be nested (should not be happening
    now, but might hppen once we add more API).
    
    And more importantly, we don't want to allow undo for password entries.

 gtk/gtkentry.c | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)
---
diff --git a/gtk/gtkentry.c b/gtk/gtkentry.c
index c83f5afc7d..8a3e481bd0 100644
--- a/gtk/gtkentry.c
+++ b/gtk/gtkentry.c
@@ -5815,6 +5815,26 @@ struct _GtkEntryRecording {
   GtkEntrySnapshot snapshot;
 };
 
+static gboolean
+gtk_entry_should_record (GtkEntry *entry)
+{
+  GtkEntryPrivate *priv = entry->priv;
+
+  /* Password entries should not allow undo because
+   * the undo stack might otherwise contain sensitive
+   * information about passwords.
+   */
+  if (!priv->visible)
+    return FALSE;
+
+  /* Somebody is already recording and recording the same
+   * thing twice makes no sense. */
+  if (priv->undo_mode == GTK_ENTRY_UNDO_RECORD)
+    return FALSE;
+
+  return TRUE;
+}
+
 static GtkEntryRecording *
 gtk_entry_start_recording (GtkEntry *entry)
 {
@@ -5822,6 +5842,9 @@ gtk_entry_start_recording (GtkEntry *entry)
 
   g_return_val_if_fail (GTK_IS_ENTRY (entry), NULL);
 
+  if (!gtk_entry_should_record (entry))
+    return NULL;
+
   recording = g_slice_new0 (GtkEntryRecording);
   recording->old_mode = gtk_entry_set_undo_mode (entry, GTK_ENTRY_UNDO_RECORD);
   gtk_entry_snapshot_init_from_entry (&recording->snapshot, entry);
@@ -5835,7 +5858,9 @@ gtk_entry_end_recording (GtkEntry          *entry,
                          gboolean           commit)
 {
   g_return_if_fail (GTK_IS_ENTRY (entry));
-  g_return_if_fail (recording != NULL);
+
+  if (recording == NULL)
+    return;
 
   if (commit)
     {