- utf16 length detection was incorrect for utf16 with surrogate pairs.

Author: lerno

lib/std/core/conv.c3

@@ -289,7 +289,8 @@ macro sz utf8_len_for_char16(Char16 c) @local
 {
 	switch
 	{
-		case c & UTF16_SURROGATE_GENERIC_MASK == UTF16_SURROGATE_GENERIC_VALUE: return 4;
+		case c & UTF16_SURROGATE_MASK == UTF16_SURROGATE_HIGH_VALUE: return 4;
+		case c & UTF16_SURROGATE_MASK == UTF16_SURROGATE_LOW_VALUE: return 0;
 		case c <= 0x7f: return 1;
 		case c <= 0x7ff: return 2;
 		default: return 3;

releasenotes.md

@@ -87,6 +87,7 @@
 - `conv::utf8to32` would not zero terminate in when the zero would be at the end of the buffer.
 - `char16_to_utf8_unsafe` would not load low byte unaligned when required.
 - Not all invalid UTF8 was detected.
+- UTF16 length detection was incorrect for utf16 with surrogate pairs.
 
 ## 0.8.0 Change list