1 files changed, 1 insertions, 0 deletions
diff --git a/lib/util.c b/lib/util.c
index 539afa2..2ace7f7 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -279,6 +279,7 @@ size_t _bmUtf8RuneInsert(char **inOutString, size_t *inOutBufSize, size_t start,
     char *str = *inOutString + start;
     memmove(str + u8len, str, len - start);
     memcpy(str, rune, u8len);
+    (*inOutString)[len + u8len] = 0;
 
     if (outRuneWidth)
         *outRuneWidth = _bmUtf8RuneWidth(rune, u8len);