[gegl] Bug 793937 - Crash in connection with median blur

[N/A <ell src gnome org>]

commit 8a69e32fe674deb5abc248b8e25eff16e4abbe9a
Author: Ell <ell_se yahoo com>
Date:   Wed Feb 28 16:29:43 2018 -0500

    Bug 793937 - Crash in connection with median blur
    
    In convert_values_to_bins(), when quantize == FALSE, sort the
    values *before* initializing prev_value, since it has to initially
    correspond to the value of the first bin, i.e., the first value
    after sorting.  Failing to do this could lead to a buffer overflow
    of bin_values, when all input values are unique.

 operations/common/median-blur.c |   10 ++++++----
 1 files changed, 6 insertions(+), 4 deletions(-)
---
diff --git a/operations/common/median-blur.c b/operations/common/median-blur.c
index 4debd6c..a8b1247 100644
--- a/operations/common/median-blur.c
+++ b/operations/common/median-blur.c
@@ -556,10 +556,14 @@ convert_values_to_bins (Histogram *hist,
 
       for (c = 0; c < n_components; c++)
         {
-          gint    bin        = 0;
-          gfloat  prev_value = values[0].value;
+          gint    bin = 0;
+          gfloat  prev_value;
           gfloat *bin_values;
 
+          sort_input_values (&values, &scratch, n_pixels);
+
+          prev_value = values[0].value;
+
           bin_values    = g_new (gfloat, n_pixels);
           bin_values[0] = prev_value;
           if (c == n_color_components)
@@ -568,8 +572,6 @@ convert_values_to_bins (Histogram *hist,
                                         (gfloat) (1 << 10) + 0.5f);
             }
 
-          sort_input_values (&values, &scratch, n_pixels);
-
           for (i = 0; i < n_pixels; i++)
             {
               gint32 *p = &src[values[i].index * n_components + c];