[gnumeric] ebd0: handle nan, just in case.

[Morten Welinder <mortenw src gnome org>]

commit 94cb08e097e2c90b8869f17053c1360ee83e533d
Author: Morten Welinder <terra gnome org>
Date:   Thu Jan 7 09:32:11 2016 -0500

    ebd0: handle nan, just in case.

 src/mathfunc.c |   26 ++++++++++++++++----------
 1 files changed, 16 insertions(+), 10 deletions(-)
---
diff --git a/src/mathfunc.c b/src/mathfunc.c
index 85fed5b..bb7c598 100644
--- a/src/mathfunc.c
+++ b/src/mathfunc.c
@@ -248,21 +248,25 @@ ebd0(gnm_float x, gnm_float M, gnm_float *yh, gnm_float *yl)
        const int N = G_N_ELEMENTS(bd0_scale) - 1;
        const double e4 = GNM_EPSILON * GNM_EPSILON * GNM_EPSILON * GNM_EPSILON;
 
+       if (gnm_isnan (x) || gnm_isnan (M)) {
+               *yl = *yh = x;
+               return;
+       }
+
        *yl = *yh = 0;
 
        if (x == M) return;
-       if (x < M * e4) { PAIR_ADD(M, *yh, *yl); return; }
+       if (x < M * e4) { ADD1(M); return; }
        if (M == 0) { *yh = gnm_pinf; return; }
 
        if (M < x * e4) {
-               PAIR_ADD(x * (gnm_log(x) - 1), *yh, *yl);
-               PAIR_ADD(-x * gnm_log(M), *yh, *yl);
+               ADD1(x * (gnm_log(x) - 1));
+               ADD1(-x * gnm_log(M));
                return;
        }
 
 #ifdef DEBUG_EBD0
        g_printerr ("x=%.20g  M=%.20g\n", x, M);
-       g_printerr ("x/M=%.20g\n", x / M);
 #endif
 
        r = gnm_frexp (M / x, &e);
@@ -293,22 +297,24 @@ ebd0(gnm_float x, gnm_float M, gnm_float *yh, gnm_float *yl)
         */
 
        for (j = G_N_ELEMENTS(bd0_scale[i]) - 1; j >= 0; j--) {
-               PAIR_ADD(x * bd0_scale[i][j], *yh, *yl);       /* Handles x*log(fg*2^e) */
-               PAIR_ADD(-x * e * bd0_scale[0][j], *yh, *yl);  /* Handles x*log(1/2^e) */
+               ADD1(x * bd0_scale[i][j]);      /* Handles x*log(fg*2^e) */
+               ADD1(-x * e * bd0_scale[0][j]); /* Handles x*log(1/2^e) */
        }
 
-       PAIR_ADD(M, *yh, *yl);
+       ADD1(M);
        M1 = gnm_floor (M + 0.5);
-       PAIR_ADD(-M1 * fg, *yh, *yl);
-       PAIR_ADD(-(M-M1) * fg, *yh, *yl);
+       ADD1(-M1 * fg);
+       ADD1(-(M-M1) * fg);
 
-       PAIR_ADD(-x * log1pmx ((M * fg - x) / x), *yh, *yl);
+       ADD1(-x * log1pmx ((M * fg - x) / x));
 
 #ifdef DEBUG_EBD0
        g_printerr ("res=%.20g + %.20g\n", *yh, *yl);
 #endif
 }
 
+#undef ADD1
+
 /* Legacy function.  */
 static gnm_float
 bd0(gnm_float x, gnm_float M)