2 files changed, 29 insertions, 23 deletions

diff --git a/source/blender/blenlib/BLI_string_utf8.h b/source/blender/blenlib/BLI_string_utf8.h
index d20cbd2a91c..adef843d2cc 100644
--- a/source/blender/blenlib/BLI_string_utf8.h
+++ b/source/blender/blenlib/BLI_string_utf8.h
@@ -51,8 +51,10 @@ char        *BLI_str_prev_char_utf8(const char *p);
 
 /* wchar_t functions, copied from blenders own font.c originally */
 size_t       BLI_wstrlen_utf8(const wchar_t *src);
+size_t       BLI_strlen_utf8_ex(const char *strc, int *r_len_bytes);
 size_t       BLI_strlen_utf8(const char *strc);
-size_t       BLI_strnlen_utf8(const char *start, const size_t maxlen);
+size_t       BLI_strnlen_utf8_ex(const char *strc, const size_t maxlen, int *r_len_bytes);
+size_t       BLI_strnlen_utf8(const char *strc, const size_t maxlen);
 size_t       BLI_strncpy_wchar_as_utf8(char *__restrict dst, const wchar_t *__restrict src, const size_t maxcpy);
 size_t       BLI_strncpy_wchar_from_utf8(wchar_t *__restrict dst, const char *__restrict src, const size_t maxcpy);
 
diff --git a/source/blender/blenlib/intern/string_utf8.c b/source/blender/blenlib/intern/string_utf8.c
index b8dca95ae33..ab0073a7585 100644
--- a/source/blender/blenlib/intern/string_utf8.c
+++ b/source/blender/blenlib/intern/string_utf8.c
@@ -245,24 +245,16 @@ size_t BLI_wstrlen_utf8(const wchar_t *src)
 	return len;
 }
 
-/* this is very close to 'BLI_str_utf8_size' functionality, perhaps we should de-duplicate */
-/* size of UTF-8 character in bytes */
-static size_t strlen_utf8_char(const char *strc)
+size_t BLI_strlen_utf8_ex(const char *strc, int *r_len_bytes)
 {
-	if ((*strc & 0xe0) == 0xc0) {
-		if ((strc[1] & 0x80) && (strc[1] & 0x40) == 0x00)
-			return 2;
-	}
-	else if ((*strc & 0xf0) == 0xe0) {
-		if ((strc[1] & strc[2] & 0x80) && ((strc[1] | strc[2]) & 0x40) == 0x00)
-			return 3;
-	}
-	else if ((*strc & 0xf8) == 0xf0) {
-		if ((strc[1] & strc[2] & strc[3] & 0x80) && ((strc[1] | strc[2] | strc[3]) & 0x40) == 0x00)
-			return 4;
-	}
+	size_t len;
+	const char *strc_orig = strc;
 
-	return 1;
+	for (len = 0; *strc; len++)
+		strc += BLI_str_utf8_size_safe(strc);
+
+	*r_len_bytes = (strc - strc_orig);
+	return len;
 }
 
 size_t BLI_strlen_utf8(const char *strc)
@@ -270,25 +262,37 @@ size_t BLI_strlen_utf8(const char *strc)
 	size_t len;
 
 	for (len = 0; *strc; len++)
-		strc += strlen_utf8_char(strc);
+		strc += BLI_str_utf8_size_safe(strc);
 
 	return len;
 }
 
+size_t BLI_strnlen_utf8_ex(const char *strc, const size_t maxlen, int *r_len_bytes)
+{
+	size_t len;
+	const char *strc_orig = strc;
+	const char *strc_end = strc + maxlen;
+
+	for (len = 0; *strc && strc < strc_end; len++) {
+		strc += BLI_str_utf8_size_safe(strc);
+	}
+
+	*r_len_bytes = (strc - strc_orig);
+	return len;
+}
+
 /**
  * \param start the string to measure the length.
  * \param maxlen the string length (in bytes)
  * \return the unicode length (not in bytes!)
  */
-size_t BLI_strnlen_utf8(const char *start, const size_t maxlen)
+size_t BLI_strnlen_utf8(const char *strc, const size_t maxlen)
 {
-	const char *strc = start;
-	const char *strc_end = start + maxlen;
-
 	size_t len;
+	const char *strc_end = strc + maxlen;
 
 	for (len = 0; *strc && strc < strc_end; len++) {
-		strc += strlen_utf8_char(strc);
+		strc += BLI_str_utf8_size_safe(strc);
 	}
 
 	return len;