From 856aaaa2de05b875a51f4b728ccf85e76ed3d91c Mon Sep 17 00:00:00 2001
From: Benjamin Ramser <legionaerr@googlemail.com>
Date: Mon, 4 Jul 2022 13:59:38 +0200
Subject: [PATCH] fix: filter by zoom level for min/max zoom 0

Prior to this, setting min_zoom=0 and max_zoom=0 would result
in the layer being present across the entire zoom range.
---
 atlas/map.go      |  2 +-
 atlas/map_test.go | 52 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/atlas/map.go b/atlas/map.go
index abb109190..2b635e5b4 100644
--- a/atlas/map.go
+++ b/atlas/map.go
@@ -145,7 +145,7 @@ func (m Map) FilterLayersByZoom(zoom uint) Map {
 	var layers []Layer
 
 	for i := range m.Layers {
-		if (m.Layers[i].MinZoom <= zoom || m.Layers[i].MinZoom == 0) && (m.Layers[i].MaxZoom >= zoom || m.Layers[i].MaxZoom == 0) {
+		if m.Layers[i].MinZoom <= zoom && m.Layers[i].MaxZoom >= zoom {
 			layers = append(layers, m.Layers[i])
 			continue
 		}
diff --git a/atlas/map_test.go b/atlas/map_test.go
index be889330b..0642a95f0 100644
--- a/atlas/map_test.go
+++ b/atlas/map_test.go
@@ -81,6 +81,58 @@ func TestMapFilterLayersByZoom(t *testing.T) {
 				},
 			},
 		},
+		{
+			atlasMap: atlas.Map{
+				Layers: []atlas.Layer{
+					{
+						Name:    "layer1",
+						MinZoom: 0,
+						MaxZoom: 0,
+					},
+					{
+						Name:    "layer2",
+						MinZoom: 1,
+						MaxZoom: 5,
+					},
+				},
+			},
+			zoom: 2,
+			expected: atlas.Map{
+				Layers: []atlas.Layer{
+					{
+						Name:    "layer2",
+						MinZoom: 1,
+						MaxZoom: 5,
+					},
+				},
+			},
+		},
+		{
+			atlasMap: atlas.Map{
+				Layers: []atlas.Layer{
+					{
+						Name:    "layer1",
+						MinZoom: 0,
+						MaxZoom: 0,
+					},
+					{
+						Name:    "layer2",
+						MinZoom: 1,
+						MaxZoom: 5,
+					},
+				},
+			},
+			zoom: 0,
+			expected: atlas.Map{
+				Layers: []atlas.Layer{
+					{
+						Name:    "layer1",
+						MinZoom: 0,
+						MaxZoom: 0,
+					},
+				},
+			},
+		},
 	}
 
 	for i, tc := range testcases {