[goffice] Avoid issues in histograms with -INFINITY and the like.

[Jean Bréfort <jbrefort src gnome org>]

commit 661cd0f025711cd3649945307c37ebd835376b24
Author: Jean Brefort <jean brefort normalesup org>
Date:   Fri Mar 11 12:05:50 2016 +0100

    Avoid issues in histograms with -INFINITY and the like.

 ChangeLog                            |    5 +++++
 plugins/plot_distrib/gog-histogram.c |   22 +++++++++++++---------
 2 files changed, 18 insertions(+), 9 deletions(-)
---
diff --git a/ChangeLog b/ChangeLog
index 3109cc2..070fa0f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2016-03-11  Jean Brefort  <jean brefort normalesup org>
+
+       * plugins/plot_distrib/gog-histogram.c
+       (gog_histogram_plot_series_update): avoid issues with -INFINITY as well.
+
 2016-03-10  Jean Brefort  <jean brefort normalesup org>
 
        * plugins/plot_distrib/gog-histogram.c
diff --git a/plugins/plot_distrib/gog-histogram.c b/plugins/plot_distrib/gog-histogram.c
index 9f505f4..16f50a7 100644
--- a/plugins/plot_distrib/gog-histogram.c
+++ b/plugins/plot_distrib/gog-histogram.c
@@ -918,7 +918,7 @@ static void
 gog_histogram_plot_series_update (GogObject *obj)
 {
        double *x_vals = NULL, *y_vals = NULL, *y__vals = NULL, cur;
-       int x_len = 1, y_len = 0, y__len = 0, max, nb = 0, i;
+       int x_len = 1, y_len = 0, y__len = 0, max, nb = 0, i, y_0 = 0, y__0 = 0;
        GogHistogramPlotSeries *series = GOG_HISTOGRAM_PLOT_SERIES (obj);
        unsigned old_num = series->base.num_elements;
        GSList *ptr;
@@ -975,22 +975,26 @@ gog_histogram_plot_series_update (GogObject *obj)
                double *y = NULL, *y_ = NULL;
                if (y_vals) {
                        y = go_range_sort (y_vals, y_len);
-                       while (y_len > 0 && !go_finite (y[y_len-1]))
+                       while (y_0 < y_len && !go_finite (y[y_0]))
+                               y_0++;
+                       while (y_len > y_0 && !go_finite (y[y_len-1]))
                                y_len--;
                }
                if (y__vals) {
                        y_ = go_range_sort (y__vals, y__len);
-                       while (y__len > 0 && !go_finite (y_[y__len-1]))
+                       while (y__0 < y__len && !go_finite (y[y__0]))
+                               y__0++;
+                       while (y__len > y__0 && !go_finite (y_[y__len-1]))
                                y__len--;
                }
                if (!x_vals || x_len <= 1) {
                        /* guess reasonable values */
                        if (width <= 0) {
                                max = go_fake_round (sqrt (MAX (y_len, y__len)));
-                               if (y && y_len > 2)
-                                       width = (y[y_len-1] - y[0]) / max;
-                               if (y_ && y__len > 2) {
-                                       double w_ = (y_[y__len-1] - y_[0]) / max;
+                               if (y && y_len - y_0 > 2)
+                                       width = (y[y_len-1] - y[y_0]) / max;
+                               if (y_ && y__len - y__0 > 2) {
+                                       double w_ = (y_[y__len-1] - y_[y__0]) / max;
                                        width = MAX (width, w_);
                                }
                                if (width > 0.) {
@@ -1011,10 +1015,10 @@ gog_histogram_plot_series_update (GogObject *obj)
                                double m, M, nm;
                                /* ignore nans */
                                if (y) {
-                                       m = y_ ? (MIN (y[0], y_[0])) : y[0];
+                                       m = y_ ? (MIN (y[y_0], y_[y__0])) : y[y_0];
                                        M = y_ ? MAX (y[y_len-1], y_[y__len-1]) : y[y_len-1];
                                } else {
-                                       m = y_[0];
+                                       m = y_[y__0];
                                        M = y_[y__len-1];
                                }
                                if (!go_finite (m) || !go_finite (M))