Function reencode_string_iconv

utf8.c:486–540

	typedef char * iconv_ibp;
#endif
char *reencode_string_iconv(const char *in, size_t insz, iconv_t conv,
			    size_t bom_len, size_t *outsz_p)
{
	size_t outsz, outalloc;
	char *out, *outpos;
	iconv_ibp cp;

	outsz = insz;
	outalloc = st_add(outsz, 1 + bom_len); /* for terminating NUL */
	out = xmalloc(outalloc);
	outpos = out + bom_len;
	cp = (iconv_ibp)in;

	while (1) {
		size_t cnt = iconv(conv, &cp, &insz, &outpos, &outsz);

		if (cnt == (size_t) -1) {
			size_t sofar;
			if (errno != E2BIG) {
				free(out);
				return NULL;
			}
			/* insz has remaining number of bytes.
			 * since we started outsz the same as insz,
			 * it is likely that insz is not enough for
			 * converting the rest.
			 */
			sofar = outpos - out;
			outalloc = st_add3(sofar, st_mult(insz, 2), 32);
			out = xrealloc(out, outalloc);
			outpos = out + sofar;
			outsz = outalloc - sofar - 1;
#ifdef ICONV_RESTART_RESET
			/*
			 * If iconv(3) messes up piecemeal conversions
			 * then restore the original pointers, sizes,
			 * and converter state, then retry converting
			 * the full string using the reallocated buffer.
			 */
			insz += cp - (iconv_ibp)in; /* Restore insz */
			cp = (iconv_ibp)in;         /* original start value */
			outpos = out + bom_len;     /* original start value */
			outsz = outalloc - bom_len - 1; /* new len */
			iconv(conv, NULL, NULL, NULL, NULL); /* reset iconv machinery */
#endif
		}
		else {
			*outpos = '\0';
			if (outsz_p)
				*outsz_p = outpos - out;
			break;
		}
	}
	return out;
}

static const char *fallback_encoding(const char *name)
{