Description of problem: 
ncurses functions malfunction for UTF-8 locale; e.g. mvaddnstr() macro 
interprets its argument as byte count, not characters. This breaks some 
3rd party applications, e.g. the 'tin' (http://www.tin.org) newsreader. 
 
Version-Release number of selected component (if applicable): 
Tries with both ncurses-5.2-28 (RedHat Linux 8.0) and ncurses-5.3-4 (RedHat 
Linux 8.1 beta 3). 
 
How reproducible: 
The sample program is below; compile with gcc -o tst tst.c -lncurses : 
 
#include <ncurses.h> 
#include <stdio.h> 
 
int main(int argc, char *argv[]) 
{ 
        initscr(); 
        mvaddnstr(15, 15, argv[1], 10); 
        refresh(); 
        sleep(5); 
        endwin(); 
        return 0; 
} 
 
Try running it with 1st argument containing only ASCII characters, e.g. 
> ./tst ThisIsALongString 
It outputs the 'ThisIsALon' string, just as expected. Then try to pass it 
any string containing multibyte characters and see it truncated to less  
than 10 characters (e.g. to 5 characters for cyrillic strings, with 
LANG=ru_RU.UTF-8)