[sysprof] scrollmap: tweak box generation a bit for safety

[Christian Hergert <chergert src gnome org>]

commit 0378b0727b6b6b49762b700f89381a276574c0b0
Author: Christian Hergert <chergert redhat com>
Date:   Tue Jul 30 15:17:16 2019 -0700

    scrollmap: tweak box generation a bit for safety

 src/libsysprof-ui/sysprof-scrollmap.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/src/libsysprof-ui/sysprof-scrollmap.c b/src/libsysprof-ui/sysprof-scrollmap.c
index 41d4478..95dc71c 100644
--- a/src/libsysprof-ui/sysprof-scrollmap.c
+++ b/src/libsysprof-ui/sysprof-scrollmap.c
@@ -78,7 +78,7 @@ sysprof_scrollmap_recalculate_worker (GTask        *task,
   g_assert (!cancellable || G_IS_CANCELLABLE (cancellable));
 
   duration = state->end_time - state->begin_time;
-  n_buckets = MAX (1, state->width / (BOX_SIZE + 1));
+  n_buckets = MAX (10, state->width / (BOX_SIZE + 1));
   buckets = g_array_sized_new (FALSE, TRUE, sizeof (gint), n_buckets);
   g_array_set_size (buckets, n_buckets);
 
@@ -90,7 +90,7 @@ sysprof_scrollmap_recalculate_worker (GTask        *task,
       if (t < state->begin_time || t > state->end_time)
         continue;
 
-      n = ((t - state->begin_time) / (gdouble)duration) * n_buckets;
+      n = MIN (n_buckets - 1, ((t - state->begin_time) / (gdouble)duration) * n_buckets);
 
       g_assert (n < n_buckets);