[gimp] Bug 788394 - Crash (segmentation fault) when calculating a histogram ...

[N/A <ell src gnome org>]

commit b2b6552f1fe60ad2f276c537ca4cede3d2a1c362
Author: Ell <ell_se yahoo com>
Date:   Tue Nov 7 18:11:24 2017 -0500

    Bug 788394 - Crash (segmentation fault) when calculating a histogram ...
    
    ... upon NaN values
    
    Make the histogram bin calculation NaN-safe, by mapping NaNs to 0.
    Ideally, NaNs should probably not be counted at all, but since we
    already count negative values as 0, and > 1 values as 1, we might
    as well not pessimize performance over it, at least until we add
    support for unbounded histograms.
    
    At the same time, improve rounding in the bin calculation, so that
    the result is more accurate.

 app/core/gimphistogram.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)
---
diff --git a/app/core/gimphistogram.c b/app/core/gimphistogram.c
index 1f50e36..1cf92d8 100644
--- a/app/core/gimphistogram.c
+++ b/app/core/gimphistogram.c
@@ -237,6 +237,7 @@ gimp_histogram_calculate (GimpHistogram       *histogram,
   const Babl           *format;
   gint                  n_components;
   gint                  n_bins;
+  gint                  temp;
 
   g_return_if_fail (GIMP_IS_HISTOGRAM (histogram));
   g_return_if_fail (GEGL_IS_BUFFER (buffer));
@@ -324,9 +325,9 @@ gimp_histogram_calculate (GimpHistogram       *histogram,
                               babl_format ("Y float"),
                               GEGL_ACCESS_READ, GEGL_ABYSS_NONE);
 
-#define VALUE(c,i) (priv->values[(c) * priv->n_bins + \
-                                 (gint) (CLAMP ((i), 0.0, 1.0) * \
-                                         (priv->n_bins - 0.0001))])
+#define VALUE(c,i) (*(temp = SIGNED_ROUND ((i) * (priv->n_bins - 1)),    \
+                      &priv->values[(c) * priv->n_bins +                 \
+                                    CLAMP (temp, 0, priv->n_bins - 1)]))
 
   while (gegl_buffer_iterator_next (iter))
     {