Bug 28552

wcstombs(3) converts wide characters to multibyte characters
incorrectly if the character is codeset 3 or codeset 4 of EUC
character.  The produced multibyte characters do not conform to EUC
specifition.

How-To-Repeat: 
#include <locale.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* multibyte Japanese EUC characters */
const unsigned char teststr[] = { 0x41, 0xa4, 0xa2, 0x8e, 0xb1,
	0x8f, 0xb0, 0xa1, 0 };

/* expected wide characters of above */
const wchar_t w_teststr[] = { 0x0041, 0xa4a2, 0x00b1, 0xb021, 0 };

void
dumpmbs(const char *prompt, const unsigned char *p)
{
	int c;

	printf("%s: ", prompt);
	do {
		c = *p++;
		printf("[%02x]", c);
	} while (c != 0);
	putchar('\n');
}

void
dumpwcs(const char *prompt, const wchar_t *wp)
{
	wchar_t wc;

	printf("%s: ", prompt);
	do {
		wc = *wp++;
		printf("[%04x]", wc);
	} while (wc != 0);
	putchar('\n');
}
	
int
main(int argc, char **argv)
{
	unsigned char buf[BUFSIZ];
	wchar_t wbuf[BUFSIZ];

	setlocale(LC_CTYPE, "ja_JP.EUC");

	strncpy(buf, teststr, sizeof(buf) - 1);
	buf[sizeof(buf) - 1] = '\0';
	
	dumpmbs("mbs", teststr);
	dumpwcs("wcs", w_teststr);

	mbstowcs(wbuf, teststr, BUFSIZ);
	dumpwcs("mbs->wcs", wbuf);

	wcstombs(buf, w_teststr, BUFSIZ);
	dumpmbs("wcs->mbs", buf);

	mbstowcs(wbuf, teststr, BUFSIZ);
	wcstombs(buf, wbuf, BUFSIZ);
	dumpmbs("mbs->wcs->mbs", buf);

	wcstombs(buf, w_teststr, BUFSIZ);
	mbstowcs(wbuf, buf, BUFSIZ);
	dumpwcs("wcs->mbs->wcs", wbuf);

	return 0;
}