1 files changed, 31 insertions, 7 deletions
diff --git a/awkgram.y b/awkgram.y
index a5707429..30ac56a9 100644
--- a/awkgram.y
+++ b/awkgram.y
@@ -1977,15 +1977,39 @@ void
 negate_num(NODE *n)
 {
 #ifdef HAVE_MPFR
-	if (is_mpg_float(n)) {
-		int tval;
-		tval = mpfr_neg(n->mpg_numbr, n->mpg_numbr, ROUND_MODE);
-		IEEE_FMT(n->mpg_numbr, tval);
-	} else if (is_mpg_integer(n)) {
-		mpz_neg(n->mpg_i, n->mpg_i);
-	} else
+	int tval = 0;
 #endif
+
+	if (! is_mpg_number(n)) {
 		n->numbr = -n->numbr;
+		return;
+	}
+
+#ifdef HAVE_MPFR
+	if (is_mpg_integer(n)) {
+		if (! iszero(n)) {
+			mpz_neg(n->mpg_i, n->mpg_i);
+			return;
+		}
+
+		/*
+		 * 0 --> -0 conversion. Requires turning the MPG integer
+		 * into an MPFR float.
+		 */
+
+		mpz_clear(n->mpg_i);	/* release the integer storage */
+
+		/* Convert and fall through. */
+		tval = mpfr_set_d(n->mpg_numbr, 0.0, ROUND_MODE);
+		IEEE_FMT(n->mpg_numbr, tval);
+		n->flags &= ~MPZN;
+		n->flags |= MPFN;
+	}
+
+	/* mpfr float case */
+	tval = mpfr_neg(n->mpg_numbr, n->mpg_numbr, ROUND_MODE);
+	IEEE_FMT(n->mpg_numbr, tval);
+#endif
 }
 
 /* print_included_from --- print `Included from ..' file names and locations */