ScriptFu: fix #11954 err call PDB file-export-foo type GimpExportOption

GimpExportOptions is incomplete.
It exists so the API is stable.
For now, ScriptFu eat and ignore actual args,
binding to NULL, in calls to PDB procedures
file-export-foo having formal args of this type.

Unlikely that in the future ScriptFu will do anything else:
if a plugin needs export options, use another language.
The few file exporters used by existing ScriptFu scripts
(file-gbr-export and file-pat-export)
don't honor export options.

libgimpbase/gimpexportoptions.h

@@ -32,7 +32,8 @@ G_BEGIN_DECLS
 /* For information look into the C source or the html documentation */
 
 
-#define GIMP_TYPE_EXPORT_OPTIONS (gimp_export_options_get_type ())
+#define GIMP_TYPE_EXPORT_OPTIONS               (gimp_export_options_get_type ())
+#define GIMP_VALUE_HOLDS_EXPORT_OPTIONS(value) (G_TYPE_CHECK_VALUE_TYPE ((value), GIMP_TYPE_EXPORT_OPTIONS))
 G_DECLARE_FINAL_TYPE (GimpExportOptions, gimp_export_options, GIMP, EXPORT_OPTIONS, GObject)
 
 

plug-ins/script-fu/libscriptfu/scheme-wrapper.c

@@ -1388,6 +1388,20 @@ script_fu_marshal_procedure_call (scheme   *sc,
               g_value_set_object (&value, resource);
             }
         }
+      else if (GIMP_VALUE_HOLDS_EXPORT_OPTIONS (&value))
+        {
+          /* ExportOptions is work in progress.
+           * For now, you can't instantiate (no gimp_export_options_new())
+           * and a script must always pass the equivalent of NULL
+           * when calling PDB functions having formal arg type ExportOptions.
+           *
+           * TEMPORARY: eat the actual Scheme arg but bind to C NULL.
+           * FUTURE: (unlikely) ScriptFu plugins can use non-NULL export options.
+           * check Scheme type of actual arg, must be int ID
+           * create a GimpExportOptions (actually a proxy?)
+           */
+            g_value_set_object (&value, NULL);
+        }
       else
         {
           g_snprintf (error_str, sizeof (error_str),

plug-ins/script-fu/scripts/mkbrush.scm

@@ -49,7 +49,8 @@
     (gimp-context-set-background '(0 0 0))
     (gimp-drawable-edit-fill drawable FILL-BACKGROUND)
 
-    (file-gbr-export 1 img filename spacing name)
+    ; -1: NULL export_options
+    (file-gbr-export 1 img filename -1 spacing name)
     (gimp-image-delete img)
 
     (gimp-context-pop)
@@ -119,7 +120,7 @@
     (gimp-context-set-background '(0 0 0))
     (gimp-drawable-edit-fill drawable FILL-BACKGROUND)
 
-    (file-gbr-export 1 img filename spacing name)
+    (file-gbr-export 1 img filename -1 spacing name)
     (gimp-image-delete img)
 
     (gimp-context-pop)
@@ -175,7 +176,7 @@
 
     (gimp-drawable-edit-fill drawable FILL-BACKGROUND)
 
-    (file-gbr-export 1 img filename spacing name)
+    (file-gbr-export 1 img filename -1 spacing name)
     (gimp-image-delete img)
 
     (gimp-context-pop)
@@ -244,7 +245,7 @@
     (gimp-context-set-background '(0 0 0))
     (gimp-drawable-edit-fill drawable FILL-BACKGROUND)
 
-    (file-gbr-export 1 img filename spacing name)
+    (file-gbr-export 1 img filename -1 spacing name)
     (gimp-image-delete img)
 
     (gimp-context-pop)

plug-ins/script-fu/scripts/paste-as-brush.scm

@@ -47,6 +47,7 @@
         (file-gbr-export RUN-NONINTERACTIVE
                          brush-image
                          path
+                         -1   ; NULL ExportOptions
                          spacing name)
 
         (gimp-image-delete brush-image)

plug-ins/script-fu/scripts/paste-as-pattern.scm

@@ -33,6 +33,7 @@
         (file-pat-export RUN-NONINTERACTIVE
                        pattern-image
                        path
+                       -1  ; NULL ExportOptions
                        name)
 
         (gimp-image-delete pattern-image)