From: Timo Sirainen <tss@iki.fi>
Date: Tue, 2 Jun 2015 22:03:52 +0000 (+0300)
Subject: lib: Added UTF8_IS_START_SEQ() helper macro
X-Git-Tag: 2.2.19.rc1~378
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=3b02371c120dcd455a09148abc5a3f520880fef2;p=thirdparty%2Fdovecot%2Fcore.git

lib: Added UTF8_IS_START_SEQ() helper macro
---

diff --git a/src/lib/unichar.h b/src/lib/unichar.h
index 1841689fbb..546c8e101a 100644
--- a/src/lib/unichar.h
+++ b/src/lib/unichar.h
@@ -23,6 +23,11 @@
 	(UTF16_SURROGATE_LOW_FIRST + \
 	 (((chr) - UTF16_SURROGATE_BASE) & UTF16_SURROGATE_MASK))
 
+/* Returns TRUE if given byte is ASCII character or the beginning of a
+   multibyte UTF-8 sequence */
+#define UTF8_IS_START_SEQ(b) \
+	(((b) & 0x80) == 0 || ((b) & 0xC0) == 0xC0)
+
 #define UTF8_REPLACEMENT_CHAR_LEN 3
 
 typedef uint32_t unichar_t;