Incorrect Cursor Advancement with Wide Characters

[Chuan-kai Lin]

Greetings,

I have recently noticed some errant behavior regarding wide character
support in the tin newsreader, and upon close inspection, it appears
that the problem comes from the libncursesw library.  The problem looks
like this:

 1. Write a string ending with a wide character with addwstr or
    add_wchstr or something, or write a single wide character with
    add_wch or friends.  The exact function used seems to be irrelevant
    to the problem itself.

 2. Invoke refresh.  Observe that the cursor stops at one character
    behind where it is supposed to be, i.e. there is a space between
    the last character of the string and the cursor.

A short program that can be used to demonstrate the problem is attached
with this message.  The problem is verified under the testing release
(sarge) of Debian GNU/Linux, with package libncursesw5 5.3.20030510-1
under the LC_CTYPE=zh_TW.Big5 setting.

The incorrect cursor advancement happens only when refresh is called,
and appears to be independent to the number of add_wch calls between
refresh calls.  Please let me know if you need more information.

Thank you.

-- 
Chuan-kai Lin
http://www.csie.ntu.edu.tw/~b6506063/

ncurses-bug.c
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