BLI_string_utf8: add buffer size arg to BLI_str_utf8_from_unicode

Besides helping to avoid buffer overflow errors this reduces complexity
of BLI_str_utf32_as_utf8 which needed a special loop for the last 6
characters to avoid writing past the buffer bounds.

Also add BLI_str_utf8_from_unicode_len which only returns the length.

1 files changed, 3 insertions, 1 deletions

diff --git a/source/blender/blenlib/BLI_string_utf8.h b/source/blender/blenlib/BLI_string_utf8.h
index 937b36758f2..3b7463affc0 100644
--- a/source/blender/blenlib/BLI_string_utf8.h
+++ b/source/blender/blenlib/BLI_string_utf8.h
@@ -48,7 +48,9 @@ unsigned int BLI_str_utf8_as_unicode_step_or_error(
     const char *__restrict p, size_t p_len, size_t *__restrict index) ATTR_WARN_UNUSED_RESULT
     ATTR_NONNULL(1, 3);
 
-size_t BLI_str_utf8_from_unicode(unsigned int c, char *outbuf);
+size_t BLI_str_utf8_from_unicode_len(unsigned int c) ATTR_WARN_UNUSED_RESULT;
+size_t BLI_str_utf8_from_unicode(unsigned int c, char *outbuf, const size_t outbuf_len)
+    ATTR_NONNULL(2);
 size_t BLI_str_utf8_as_utf32(char32_t *__restrict dst_w,
                              const char *__restrict src_c,
                              const size_t maxncpy) ATTR_NONNULL(1, 2);