Fix array underrun when calculating velocity

[ext/subsurface.git] / profile.c

diff --git a/profile.c b/profile.c
index f2cc526dd7ff4f15e33d2f85be1d080d6452cd8d..3f3dd42bc108f1c0b7e048a1521388e92e1a7c2d 100644 (file)
--- a/profile.c
+++ b/profile.c
@@ -620,7 +620,7 @@ static struct plot_info *analyze_plot_info(struct plot_info *pi)
                         /* if our samples are short and we aren't too FAST*/
                        if (entry[0].sec - entry[-1].sec < 30 && entry->velocity < FAST) { 
                                int past = -2;
-                               while (pi->entry <= entry-past && entry[0].sec - entry[past].sec < 30)
+                               while (i+past > 0 && entry[0].sec - entry[past].sec < 30)
                                        past--;
                                entry->velocity = velocity((entry[0].val - entry[past].val) / 
                                                        (entry[0].sec - entry[past].sec));