X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=libs%2Fcanvas%2Fxfade_curve.cc;h=c8e477697c47679f2ebeb520830a2b69001f6f2c;hb=440618b463ff88bd42847456b1470479ce25871d;hp=0d7d7a5245b76075ee5a8b009729036bdefdea02;hpb=14ffde884fe3bb2521b2e44998804f5169760aa2;p=ardour.git

diff --git a/libs/canvas/xfade_curve.cc b/libs/canvas/xfade_curve.cc
index 0d7d7a5245..c8e477697c 100644
--- a/libs/canvas/xfade_curve.cc
+++ b/libs/canvas/xfade_curve.cc
@@ -35,7 +35,7 @@ static const bool show_bg_fades = false;
 #else
 static const bool show_bg_fades = true;
 #endif
-	
+
 XFadeCurve::XFadeCurve (Canvas* c)
 	: Item (c)
 	, points_per_segment (32)
@@ -178,14 +178,15 @@ XFadeCurve::get_path(Rect const & area, Cairo::RefPtr<Cairo::Context> context, C
 		Points::size_type left = 0;
 		Points::size_type right = c.n_samples - 1;
 
+		assert (left < right);
 		// we should really really do a binary search rather than iterate
 		for (Points::size_type idx = 0; idx < c.n_samples - 1; ++idx) {
 			left = idx;
 			window_space = item_to_window (Duple (c.samples[idx].x, 0.0), false);
 			if (window_space.x >= area.x0) break;
 		}
-		for (Points::size_type idx = c.n_samples; idx >= left;) {
-			--idx;
+		for (Points::size_type idx = c.n_samples; right > left;) {
+			if (--idx <= left) break;
 			window_space = item_to_window (Duple (c.samples[idx].x, 0.0), false);
 			if (window_space.x <= area.x1) break;
 			right = idx;
@@ -286,7 +287,7 @@ XFadeCurve::render (Rect const & area, Cairo::RefPtr<Cairo::Context> context) co
 	if (IS_START || show_background_fade) {
 		set_source_rgba (context, IS_START ? _outline_color : outline_shaded);
 		context->set_line_width (IS_START ? 1.0 : .5);
-        
+
 		context->begin_new_path ();
 		context->append_path (*path_in);
 		context->stroke();