add vips_value_set_blob_free()

simpler for language bindings to call

ChangeLog

@@ -29,6 +29,7 @@
   Warren and Nakilon
 - vector path for convolution is more accurate and can handle larger masks
 - linear and cubic kernels for reduce are higer quality
+- added vips_value_set_blob_free()
 
 29/8/17 started 8.5.9
 - make --fail stop jpeg read on any libjpeg warning, thanks @mceachen

libvips/include/vips/type.h

@@ -223,6 +223,7 @@ void vips_value_set_ref_string( GValue *value, const char *str );
 void *vips_value_get_blob( const GValue *value, size_t *length );
 void vips_value_set_blob( GValue *value, 
 	VipsCallbackFn free_fn, void *data, size_t length );
+void vips_value_set_blob_free( GValue *value, void *data, size_t length );
 
 void vips_value_set_array( GValue *value, 
 	int n, GType type, size_t sizeof_type );

libvips/iofuncs/type.c

@@ -1558,6 +1558,32 @@ vips_value_set_blob( GValue *value,
 	vips_area_unref( VIPS_AREA( blob ) );
 }
 
+/** 
+ * vips_value_set_blob_free:
+ * @value: (out): GValue to set
+ * @data: pointer to area of memory
+ * @length: length of memory area
+ *
+ * Just like vips_value_set_blob(), but when 
+ * @value is freed, @data will be
+ * freed with g_free(). 
+ *
+ * This can be easier to call for language bindings.
+ *
+ * See also: vips_value_set_blob()
+ */
+void
+vips_value_set_blob_free( GValue *value, void *data, size_t length ) 
+{
+	VipsBlob *blob;
+
+	g_assert( G_VALUE_TYPE( value ) == VIPS_TYPE_BLOB );
+
+	blob = vips_blob_new( g_free, data, length );
+	g_value_set_boxed( value, blob );
+	vips_area_unref( VIPS_AREA( blob ) );
+}
+
 /** 
  * vips_value_get_blob:
  * @value: GValue to set