constify content member in CalloutListEntry

diff --git a/src/regint.h b/src/regint.h
index 6a84fee8012dc464558dba71aa8246d1b2e95e69..bb39de88d4d1c06d89e1fd54ca372d52759ef27a 100644 (file)
--- a/src/regint.h
+++ b/src/regint.h
@@ -267,8 +267,8 @@ typedef struct {
   OnigCalloutFunc end_func;
   union {
     struct {
-      UChar* start;
-      UChar* end;
+      const UChar* start;
+      const UChar* end;
     } content;
     struct {
       int num;