babl: add decrease of bits per components to bad_idea()

related to bug #787441

diff --git a/babl/babl-fish-path.c b/babl/babl-fish-path.c
index b7133afc6355fbc7a4e241713805b3d51f0fb794..6b2874bd2a88d1beeb4a459bb6fe842e392fb48a 100644 (file)
--- a/babl/babl-fish-path.c
+++ b/babl/babl-fish-path.c
@@ -165,6 +165,13 @@ bad_idea (const Babl *from, const Babl *to, const Babl *format)
   {
     return 1;
   }
+  if (from->format.type[0]->bits > format->format.type[0]->bits)
+  {
+    /* XXX: perhaps we especially avoid going to half-float, when
+     * going between u16 formats as well? */
+    return 1;
+  }
+
   return 0;
 }