diff -Naur inkscape-1.0.2_2021-01-15_e86c870879.orig/src/3rdparty/autotrace/autotrace.h inkscape-1.0.2_2021-01-15_e86c870879/src/3rdparty/autotrace/autotrace.h
--- inkscape-1.0.2_2021-01-15_e86c870879.orig/src/3rdparty/autotrace/autotrace.h	2021-01-15 12:04:25.000000000 +0200
+++ inkscape-1.0.2_2021-01-15_e86c870879/src/3rdparty/autotrace/autotrace.h	2021-04-04 18:26:47.585580323 +0300
@@ -23,6 +23,9 @@
 
 #include <stdio.h>
 
+#include "types.h"
+#include "color.h"
+
 #ifdef __cplusplus
 extern "C" {
 #endif                          /* __cplusplus */
@@ -35,8 +38,7 @@
  * Typedefs
  * ===================================================================== */
 
-#include "types.h"
-#include "color.h"
+
 
 /* Third degree is the highest we deal with.  */
   enum _at_polynomial_degree {
diff -Naur inkscape-1.0.2_2021-01-15_e86c870879.orig/src/3rdparty/autotrace/color.h inkscape-1.0.2_2021-01-15_e86c870879/src/3rdparty/autotrace/color.h
--- inkscape-1.0.2_2021-01-15_e86c870879.orig/src/3rdparty/autotrace/color.h	2021-01-15 12:04:25.000000000 +0200
+++ inkscape-1.0.2_2021-01-15_e86c870879/src/3rdparty/autotrace/color.h	2021-04-04 18:06:05.508363694 +0300
@@ -24,6 +24,10 @@
 #include <glib.h>
 #include <glib-object.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif                          /* __cplusplus */
+
 typedef struct _at_color at_color;
 struct _at_color {
   guint8 r;
@@ -43,4 +47,8 @@
 GType at_color_get_type(void);
 #define AT_TYPE_COLOR (at_color_get_type ())
 
+#ifdef __cplusplus
+}
+#endif                          /* __cplusplus */
+
 #endif /* not AT_COLOR_H */