Discard unprintable single width characters instead.

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/util.c b/lib/util.c
index 351bb5f..c4533ca 100644
--- a/lib/util.c
+++ b/lib/util.c
@@ -242,7 +242,7 @@ size_t _bmUtf8RuneInsert(char *string, size_t bufSize, size_t start, const char
     if (len + u8len >= bufSize)
         return 0;
 
-    if (u8len == 1 && iscntrl(*rune))
+    if (u8len == 1 && !isprint(*rune))
         return 0;
 
     char *str = string + start;