Comment Comment Tcl_UniCharToUtf() better, what happens handling surrogates. Add type cast in tclUtf.c, making actual check clearer

1 files changed, 4 insertions, 3 deletions

diff --git a/doc/Utf.3 b/doc/Utf.3
index afcff79..111aae6 100644
--- a/doc/Utf.3
+++ b/doc/Utf.3
@@ -133,9 +133,10 @@ represent one Unicode character in the UTF-8 representation.
 \fBTcl_UniCharToUtf\fR stores the character \fIch\fR as a UTF-8 string
 in starting at \fIbuf\fR.  The return value is the number of bytes stored
 in \fIbuf\fR. If ch is a high surrogate (range U+D800 - U+DBFF), then
-the return value will be 0 and nothing will be stored. If you still
-want to produce UTF-8 output for it (even though knowing it's an illegal
-code-point on its own), just call \fBTcl_UniCharToUtf\fR again using ch = -1.
+the return value will be 1 and a single byte in the range 0xF0 - 0xF4
+will be stored. If you still want to produce UTF-8 output for it (even
+though knowing it's an illegal code-point on its own), just call
+\fBTcl_UniCharToUtf\fR again specifying ch = -1.
 .PP
 \fBTcl_UtfToUniChar\fR reads one UTF-8 character starting at \fIsrc\fR
 and stores it as a Tcl_UniChar in \fI*chPtr\fR.  The return value is the