From bea5f4b47def81a669f1bc0c1415f02a8b9f595b Mon Sep 17 00:00:00 2001
From: Dirk Farin <dirk.farin@gmail.com>
Date: Thu, 5 Oct 2023 12:02:47 +0200
Subject: [PATCH] provide a default heif_error_success (#970)

---
 libheif/heif.cc | 102 +++++++++++++++++++++++-------------------------
 libheif/heif.h  |   3 ++
 2 files changed, 52 insertions(+), 53 deletions(-)

diff --git a/libheif/heif.cc b/libheif/heif.cc
index c8b8f16825..f1c41769dc 100644
--- a/libheif/heif.cc
+++ b/libheif/heif.cc
@@ -58,7 +58,7 @@
 #include <cassert>
 
 
-static struct heif_error error_Ok = {heif_error_Ok, heif_suberror_Unspecified, kSuccess};
+struct heif_error heif_error_success = {heif_error_Ok, heif_suberror_Unspecified, kSuccess};
 static struct heif_error error_unsupported_parameter = {heif_error_Usage_error,
                                                         heif_suberror_Unsupported_parameter,
                                                         "Unsupported encoder parameter"};
@@ -333,7 +333,7 @@ struct heif_error heif_list_compatible_brands(const uint8_t* data, int len, heif
     (*out_brands)[i] = brands[i];
   }
 
-  return {heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
+  return heif_error_success;
 }
 
 
@@ -603,7 +603,7 @@ struct heif_error heif_context_get_image_handle(struct heif_context* ctx,
   (*imgHdl)->image = image;
   (*imgHdl)->context = ctx->context;
 
-  return {heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
+  return heif_error_success;
 }
 
 
@@ -715,7 +715,7 @@ struct heif_error heif_image_handle_get_auxiliary_type(const struct heif_image_h
   strcpy(buf, auxType.c_str());
   *out_type = buf;
 
-  return {heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
+  return heif_error_success;
 }
 
 
@@ -822,7 +822,7 @@ struct heif_error heif_image_handle_get_preferred_decoding_colorspace(const stru
     return err.error_struct(image_handle->image.get());
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -1086,8 +1086,7 @@ struct heif_error heif_image_create(int width, int height,
 
   *image = img;
 
-  struct heif_error err = {heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
-  return err;
+  return heif_error_success;
 }
 
 int heif_image_get_decoding_warnings(struct heif_image* image,
@@ -1205,7 +1204,7 @@ struct heif_error heif_mastering_display_colour_volume_decode(const struct heif_
     out->min_display_mastering_luminance = in->min_display_mastering_luminance * 0.0001;
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -1301,7 +1300,7 @@ heif_error heif_image_crop(struct heif_image* img,
 
   img->image = out_img;
 
-  return heif_error{heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
+  return heif_error_success;
 }
 
 
@@ -1333,8 +1332,7 @@ struct heif_error heif_image_add_plane(struct heif_image* image,
     return err;
   }
   else {
-    struct heif_error err = {heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
-    return err;
+    return heif_error_success;
   }
 }
 
@@ -1395,7 +1393,7 @@ struct heif_error heif_image_extend_padding_to_size(struct heif_image* image, in
                       "Cannot allocate image memory."};
   }
   else {
-    return heif_error{heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
+    return heif_error_success;
   }
 }
 
@@ -1441,8 +1439,7 @@ struct heif_error heif_image_set_raw_color_profile(struct heif_image* image,
 
   image->image->set_color_profile_icc(color_profile);
 
-  struct heif_error err = {heif_error_Ok, heif_suberror_Unspecified, Error::kSuccess};
-  return err;
+  return heif_error_success;
 }
 
 
@@ -1458,7 +1455,7 @@ struct heif_error heif_image_set_nclx_color_profile(struct heif_image* image,
 
   image->image->set_color_profile_nclx(nclx);
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -1994,7 +1991,7 @@ struct heif_error heif_item_get_property_user_description(const struct heif_cont
 
   *out = udes_c;
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -2020,7 +2017,7 @@ struct heif_error heif_item_add_property_user_description(const struct heif_cont
     *out_propertyId = id;
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -2136,7 +2133,7 @@ struct heif_error heif_register_decoder_plugin(const heif_decoder_plugin* decode
   }
 
   register_decoder(decoder_plugin);
-  return error_Ok;
+  return heif_error_success;
 }
 
 struct heif_error heif_register_encoder_plugin(const heif_encoder_plugin* encoder_plugin)
@@ -2149,7 +2146,7 @@ struct heif_error heif_register_encoder_plugin(const heif_encoder_plugin* encode
   }
 
   register_encoder(encoder_plugin);
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -2483,8 +2480,7 @@ struct heif_error heif_encoder_set_logging_level(struct heif_encoder* encoder, i
     return encoder->plugin->set_parameter_logging_level(encoder->encoder, level);
   }
 
-  struct heif_error err = {heif_error_Ok, heif_suberror_Unspecified, kSuccess};
-  return err;
+  return heif_error_success;
 }
 
 
@@ -2584,7 +2580,7 @@ heif_encoder_parameter_get_valid_integer_range(const struct heif_encoder_paramet
     *have_minimum_maximum = param->integer.have_minimum_maximum;
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 LIBHEIF_API
@@ -2632,7 +2628,7 @@ struct heif_error heif_encoder_parameter_get_valid_integer_values(const struct h
     *num_valid_values = param->integer.num_valid_values;
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -2648,7 +2644,7 @@ heif_encoder_parameter_get_valid_string_values(const struct heif_encoder_paramet
     *out_stringarray = param->string.valid_values;
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 struct heif_error heif_encoder_parameter_integer_valid_range(struct heif_encoder* encoder,
@@ -2771,7 +2767,7 @@ struct heif_error heif_encoder_set_parameter(struct heif_encoder* encoder,
           break;
       }
 
-      return error_Ok;
+      return heif_error_success;
     }
   }
 
@@ -2824,7 +2820,7 @@ struct heif_error heif_encoder_get_parameter(struct heif_encoder* encoder,
           break;
       }
 
-      return error_Ok;
+      return heif_error_success;
     }
   }
 
@@ -2965,7 +2961,7 @@ struct heif_error heif_context_encode_image(struct heif_context* ctx,
     (*out_image_handle)->context = ctx->context;
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3027,7 +3023,7 @@ struct heif_error heif_context_encode_thumbnail(struct heif_context* ctx,
     }
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3036,7 +3032,7 @@ struct heif_error heif_context_set_primary_image(struct heif_context* ctx,
 {
   ctx->context->set_primary_image(image_handle->image);
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3049,7 +3045,7 @@ struct heif_error heif_context_add_exif_metadata(struct heif_context* ctx,
     return error.error_struct(ctx->context.get());
   }
   else {
-    return error_Ok;
+    return heif_error_success;
   }
 }
 
@@ -3073,7 +3069,7 @@ struct heif_error heif_context_add_XMP_metadata2(struct heif_context* ctx,
     return error.error_struct(ctx->context.get());
   }
   else {
-    return error_Ok;
+    return heif_error_success;
   }
 }
 
@@ -3089,7 +3085,7 @@ struct heif_error heif_context_add_generic_metadata(struct heif_context* ctx,
     return error.error_struct(ctx->context.get());
   }
   else {
-    return error_Ok;
+    return heif_error_success;
   }
 }
 
@@ -3142,7 +3138,7 @@ struct heif_error heif_context_get_region_item(const struct heif_context* contex
   item->region_item = r;
   *out = item;
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3212,7 +3208,7 @@ struct heif_error heif_image_handle_add_region_item(struct heif_image_handle* im
     *out_region_item = item;
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3241,7 +3237,7 @@ struct heif_error heif_region_item_add_region_point(struct heif_region_item* ite
     *out_region = create_region(region, item);
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3262,7 +3258,7 @@ struct heif_error heif_region_item_add_region_rectangle(struct heif_region_item*
     *out_region = create_region(region, item);
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3283,7 +3279,7 @@ struct heif_error heif_region_item_add_region_ellipse(struct heif_region_item* i
     *out_region = create_region(region, item);
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3307,7 +3303,7 @@ struct heif_error heif_region_item_add_region_polygon(struct heif_region_item* i
     *out_region = create_region(region, item);
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3331,7 +3327,7 @@ struct heif_error heif_region_item_add_region_polyline(struct heif_region_item*
     *out_region = create_region(region, item);
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3361,7 +3357,7 @@ struct heif_error heif_region_item_add_region_referenced_mask(struct heif_region
   std::shared_ptr<HeifContext> ctx = item->context;
   ctx->add_region_referenced_mask_ref(item->region_item->item_id, mask_item_id);
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3386,7 +3382,7 @@ struct heif_error heif_region_item_add_region_inline_mask_data(struct heif_regio
     *out_region = create_region(region, item);
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 struct heif_error heif_region_item_add_region_inline_mask(struct heif_region_item* item,
@@ -3428,7 +3424,7 @@ struct heif_error heif_region_item_add_region_inline_mask(struct heif_region_ite
     *out_region = create_region(region, item);
   }
 
-  return error_Ok;
+  return heif_error_success;
 }
 
 
@@ -3461,7 +3457,7 @@ struct heif_error heif_region_get_point(const struct heif_region* region, int32_
   if (point) {
     *x = point->x;
     *y = point->y;
-    return heif_error_ok;
+    return heif_error_success;
   }
 
   return heif_error_invalid_parameter_value;
@@ -3484,7 +3480,7 @@ struct heif_error heif_region_get_point_transformed(const struct heif_region* re
     *x = p.x;
     *y = p.y;
 
-    return heif_error_ok;
+    return heif_error_success;
   }
 
   return heif_error_invalid_parameter_value;
@@ -3501,7 +3497,7 @@ struct heif_error heif_region_get_rectangle(const struct heif_region* region,
     *y = rect->y;
     *width = rect->width;
     *height = rect->height;
-    return heif_error_ok;
+    return heif_error_success;
   }
 
   return heif_error_invalid_parameter_value;
@@ -3526,7 +3522,7 @@ struct heif_error heif_region_get_rectangle_transformed(const struct heif_region
     *y = p.y;
     *width = e.x;
     *height = e.y;
-    return heif_error_ok;
+    return heif_error_success;
   }
 
   return heif_error_invalid_parameter_value;
@@ -3543,7 +3539,7 @@ struct heif_error heif_region_get_ellipse(const struct heif_region* region,
     *y = ellipse->y;
     *radius_x = ellipse->radius_x;
     *radius_y = ellipse->radius_y;
-    return heif_error_ok;
+    return heif_error_success;
   }
 
   return heif_error_invalid_parameter_value;
@@ -3568,7 +3564,7 @@ struct heif_error heif_region_get_ellipse_transformed(const struct heif_region*
     *y = p.y;
     *radius_x = e.x;
     *radius_y = e.y;
-    return heif_error_ok;
+    return heif_error_success;
   }
 
   return heif_error_invalid_parameter_value;
@@ -3609,7 +3605,7 @@ static struct heif_error heif_region_get_poly_points(const struct heif_region* r
       pts[2 * i + 0] = poly->points[i].x;
       pts[2 * i + 1] = poly->points[i].y;
     }
-    return heif_error_ok;
+    return heif_error_success;
   }
   return heif_error_invalid_parameter_value;
 }
@@ -3646,7 +3642,7 @@ static struct heif_error heif_region_get_poly_points_scaled(const struct heif_re
       pts[2 * i + 0] = p.x;
       pts[2 * i + 1] = p.y;
     }
-    return heif_error_ok;
+    return heif_error_success;
   }
   return heif_error_invalid_parameter_value;
 }
@@ -3680,7 +3676,7 @@ struct heif_error heif_region_get_referenced_mask_ID(const struct heif_region* r
     *width = mask->width;
     *height = mask->height;
     *mask_item_id = mask->referenced_item;
-    return heif_error_ok;
+    return heif_error_success;
   }
   return heif_error_invalid_parameter_value;
 }
@@ -3712,7 +3708,7 @@ struct heif_error heif_region_get_inline_mask_data(const struct heif_region* reg
     *width = mask->width;
     *height = mask->height;
     memcpy(data, mask->mask_data.data(), mask->mask_data.size());
-    return heif_error_ok;
+    return heif_error_success;
   }
   return heif_error_invalid_parameter_value;
 }
@@ -3763,7 +3759,7 @@ static struct heif_error heif_region_get_inline_mask_image(const struct heif_reg
         pixel_index++;
       }
     }
-    return heif_error_ok;
+    return heif_error_success;
   }
   return heif_error_invalid_parameter_value;
 }
diff --git a/libheif/heif.h b/libheif/heif.h
index a499ff2dad..71097b2e62 100644
--- a/libheif/heif.h
+++ b/libheif/heif.h
@@ -323,6 +323,9 @@ struct heif_error
   const char* message;
 };
 
+// Default success return value. Intended for use in user-supplied callback functions.
+LIBHEIF_API extern struct heif_error heif_error_success;
+
 
 typedef uint32_t heif_item_id;
 typedef uint32_t heif_property_id;