utf8: introduce git_utf8_char_length

Introduce a function to determine the number of Unicode characters in a
given UTF-8 string.

1 files changed, 18 insertions, 0 deletions

diff --git a/src/utf8.c b/src/utf8.c
index 1a37da6fb..77065cb71 100644
--- a/src/utf8.c
+++ b/src/utf8.c
@@ -114,6 +114,24 @@ int git_utf8_iterate(uint32_t *out, const char *_str, size_t str_len)
 	return length;
 }
 
+size_t git_utf8_char_length(const char *_str, size_t str_len)
+{
+	const uint8_t *str = (const uint8_t *)_str;
+	size_t offset = 0, count = 0;
+
+	while (offset < str_len) {
+		int length = utf8_charlen(str + offset, str_len - offset);
+
+		if (length < 0)
+			length = 1;
+
+		offset += length;
+		count++;
+	}
+
+	return count;
+}
+
 size_t git_utf8_valid_buf_length(const char *_str, size_t str_len)
 {
 	const uint8_t *str = (const uint8_t *)_str;