[gnumeric] Handle denormals better.

[Morten Welinder <mortenw src gnome org>]

commit bd07ea76616ac604c07abf7bb4f608db7b282d57
Author: Morten Welinder <terra gnome org>
Date:   Tue May 16 21:11:50 2017 -0400

    Handle denormals better.
    
    Accept them instead of turning things into strings that we then cannot
    deal with.

 ChangeLog    |    6 ++++++
 src/gutils.c |   14 ++++++++++++--
 src/value.c  |    3 +++
 3 files changed, 21 insertions(+), 2 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 6d82e92..1cbd108 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2017-05-16  Morten Welinder  <terra gnome org>
+
+       * src/gutils.c (gnm_utf8_strto): Handle denormals better.
+
+       * src/value.c (value_new_from_string): Handle denormals betters.
+
 2017-04-05  Morten Welinder  <terra gnome org>
 
        * src/sf-trig.c (gnm_reduce_pi): Rename from reduce_pi_half.
diff --git a/src/gutils.c b/src/gutils.c
index cfdc059..fd1337a 100644
--- a/src/gutils.c
+++ b/src/gutils.c
@@ -206,8 +206,10 @@ gnm_utf8_strto (const char *s, char **end)
        gnm_float res;
        int save_errno;
 
-       if (all_ascii (s))
-               return gnm_strto (s, end);
+       if (all_ascii (s)) {
+               res = gnm_strto (s, end);
+               goto handle_denormal;
+       }
 
        ascii = g_string_sized_new (100);
 
@@ -271,6 +273,14 @@ gnm_utf8_strto (const char *s, char **end)
        g_string_free (ascii, TRUE);
 
        errno = save_errno;
+
+handle_denormal:
+       save_errno = errno;
+       if (res != 0 && gnm_abs (res) < GNM_MIN)
+               errno = 0;
+       else
+               errno = save_errno;
+
        return res;
 }
 
diff --git a/src/value.c b/src/value.c
index d1b0daf..30e1993 100644
--- a/src/value.c
+++ b/src/value.c
@@ -510,6 +510,9 @@ value_new_from_string (GnmValueType t, char const *str, GOFormat *sf,
                gnm_float d;
 
                d = gnm_strto (str, &end);
+               if (d != 0 && d > -GNM_MIN && d < GNM_MIN)
+                       errno = 0;
+
                if (str != end && *end == '\0' && errno != ERANGE)
                        res = value_new_float (d);
                break;