AvatarChooser: clarify why _scale_down_if_necessary is cheap.

svn path=/trunk/; revision=1698

1 files changed, 7 insertions, 2 deletions

diff --git a/libempathy-gtk/empathy-avatar-chooser.c b/libempathy-gtk/empathy-avatar-chooser.c
index 31c7adca8..af6a82ef0 100644
--- a/libempathy-gtk/empathy-avatar-chooser.c
+++ b/libempathy-gtk/empathy-avatar-chooser.c
@@ -448,8 +448,13 @@ avatar_chooser_maybe_convert_and_scale (EmpathyAvatarChooser *chooser,
 		needs_conversion = TRUE;
 	}
 
-	/* If scaling down the pixbuf to fit the dimensions yields a new
-	 * pixbuf, then it needed scaling. if it's the same pixbuf, it did not.
+	/* If _scale_down_if_necessary yields a new pixbuf, then it needed
+	 * scaling.  If it's the same pixbuf, it did not, and did no extra work
+	 * beyond checking the dimensions.  Hence, we call it even if
+	 * needs_conversion is already TRUE, rather than duplicating the
+	 * dimension checking code here, as it's no more expensive than
+	 * checking the dimensions first in the case where no scaling is
+	 * necessary.
 	 */
 	pixbuf_scaled = empathy_pixbuf_scale_down_if_necessary (pixbuf,
 		MIN(max_width, max_height));