[gegl] gegl/operation: make gegl_operation_get_format always return a format

[Øyvind "pippin" Kolås <ok src gnome org>]

commit fcb978e4d8a9df62a103c5a69e8602f4b29c87c3
Author: Øyvind Kolås <pippin gimp org>
Date:   Wed Jul 13 19:22:27 2022 +0200

    gegl/operation: make gegl_operation_get_format always return a format
    
    Instead of NULL we return "RGBA float", this effectively makes it a
    default fallback format - and simplifies other parts of the code
    which can now presume a valid format to exist. This fixes issue #308.

 gegl/operation/gegl-operation-context.c | 7 -------
 gegl/operation/gegl-operation.c         | 8 +++++---
 2 files changed, 5 insertions(+), 10 deletions(-)
---
diff --git a/gegl/operation/gegl-operation-context.c b/gegl/operation/gegl-operation-context.c
index 939dcfe21..c3d9af502 100644
--- a/gegl/operation/gegl-operation-context.c
+++ b/gegl/operation/gegl-operation-context.c
@@ -323,13 +323,6 @@ gegl_operation_context_get_target (GeglOperationContext *context,
   node = operation->node; /* <ick */
   format = gegl_operation_get_format (operation, padname);
 
-  if (format == NULL)
-    {
-      g_warning ("no format for %s presuming RGBA float\n",
-                 gegl_node_get_debug_name (node));
-      format = gegl_babl_rgba_linear_float ();
-    }
-  g_assert (format != NULL);
 
   result = &context->result_rect;
 
diff --git a/gegl/operation/gegl-operation.c b/gegl/operation/gegl-operation.c
index 3de589e5a..c271aee00 100644
--- a/gegl/operation/gegl-operation.c
+++ b/gegl/operation/gegl-operation.c
@@ -560,12 +560,14 @@ gegl_operation_get_format (GeglOperation *self,
 {
   GeglPad *pad;
 
-  g_return_val_if_fail (GEGL_IS_OPERATION (self), NULL);
-  g_return_val_if_fail (pad_name != NULL, NULL);
+  g_return_val_if_fail (GEGL_IS_OPERATION (self) && pad_name != NULL,
+                  gegl_babl_rgba_linear_float ());
 
   pad = gegl_node_get_pad (self->node, pad_name);
 
-  g_return_val_if_fail (pad != NULL, NULL);
+  if (pad == NULL ||
+      pad->format == NULL)
+    return gegl_babl_rgba_linear_float ();
 
   return pad->format;
 }