diff -ruN a/mpfr.c b/mpfr.c
--- a/mpfr.c	2019-08-29 03:54:14.000000000 +0900
+++ b/mpfr.c	2020-07-08 14:00:38.477382839 +0900
@@ -293,6 +293,17 @@
 	else
 		cp1 = cp;
 
+	/*
+	 * Maybe "+" or "-" was the field.  mpg_strtoui
+	 * won't check for that and set errno, so we have
+	 * to check manually.
+	 */
+	if (*cp1 == '\0') {
+		*cpend = save;
+		mpg_zero(n);
+		return false;
+	}
+
 	if (do_nondec)
 		base = get_numbase(cp1, cpend - cp1, use_locale);
 
diff -ruN a/node.c b/node.c
--- a/node.c	2020-02-07 05:52:57.000000000 +0900
+++ b/node.c	2020-07-08 14:00:35.245287010 +0900
@@ -315,11 +315,13 @@
 		r = mpg_integer();
 		mpz_set(r->mpg_i, n->mpg_i);
 		r->flags = n->flags;
+		r->strndmode = MPFR_round_mode;
 	} else if ((n->flags & MPFN) != 0) {
 		r = mpg_float();
 		int tval = mpfr_set(r->mpg_numbr, n->mpg_numbr, ROUND_MODE);
 		IEEE_FMT(r->mpg_numbr, tval);
 		r->flags = n->flags;
+		r->strndmode = MPFR_round_mode;
 	} else {
 #endif
 		getnode(r);
@@ -342,6 +344,7 @@
 		emalloc(r->stptr, char *, n->stlen + 1, "r_dupnode");
 		memcpy(r->stptr, n->stptr, n->stlen);
 		r->stptr[n->stlen] = '\0';
+		r->stlen = n->stlen;
 		if ((n->flags & WSTRCUR) != 0) {
 			r->wstlen = n->wstlen;
 			emalloc(r->wstptr, wchar_t *, sizeof(wchar_t) * (n->wstlen + 1), "r_dupnode");