Fix: use of non UTF8 string copy for thick wrapped strings in Python

Avoid potential incomplete UTF8 sequences in the Python RNA API.

source/blender/python/intern/bpy_rna.cc

@@ -25,6 +25,7 @@
 #include "BLI_listbase.h"
 #include "BLI_math_rotation.h"
 #include "BLI_string.h"
+#include "BLI_string_utf8.h"
 #include "BLI_utildefines.h"
 #include "BLI_vector.hh"
 
@@ -1770,12 +1771,12 @@ static int pyrna_py_to_prop(
             return -1;
           }
 
-          /* Same as bytes. */
+          /* Same as bytes (except for UTF8 string copy). */
           /* XXX, this is suspect, but needed for function calls,
            * need to see if there's a better way. */
           if (data) {
             if (RNA_property_flag(prop) & PROP_THICK_WRAP) {
-              BLI_strncpy((char *)data, (char *)param, RNA_property_string_maxlength(prop));
+              BLI_strncpy_utf8((char *)data, (char *)param, RNA_property_string_maxlength(prop));
             }
             else {
               *((char **)data) = (char *)param;