From aefbc5b2f5e30e9d4649107c87a3c8851bc0dc80 Mon Sep 17 00:00:00 2001
From: Patrick Pelissier <patrick.pelissier@gmail.com>
Date: Sat, 10 Sep 2022 10:34:54 +0200
Subject: [PATCH] Factorize the test of the start of an UTF8 code point in a
 separate function

---
 m-string.h | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/m-string.h b/m-string.h
index c453e6d4..97f8663e 100644
--- a/m-string.h
+++ b/m-string.h
@@ -1646,6 +1646,13 @@ m_str1ng_utf8_valid_str_p(const char str[])
   return true;
 }
 
+/* Test if the given character is the start of an UTF8 code point */
+static inline bool
+m_str1ng_utf8_start_p(unsigned char val)
+{
+  return ((val & 0xC0u) != 0x80u);
+}
+
 /* Computer the number of unicode characters are represented in the UTF8 stream
  */
 static inline size_t
@@ -1654,7 +1661,7 @@ m_str1ng_utf8_length(const char str[])
   size_t size = 0;
   while (*str) {
     unsigned char val = (unsigned char) *str++;
-    size += ((val & 0xC0u) != 0x80u);
+    size += m_str1ng_utf8_start_p(val);
   }
   return size;
 }