From 341e77a71f555d2ae3f3c4fc2f11bc9dee05a902 Mon Sep 17 00:00:00 2001
From: Ilija Puaca <ilija@unfolded.ai>
Date: Wed, 18 Nov 2020 20:36:33 +0100
Subject: [PATCH] FIX: Prevent crash in react-map-gl when zoom cannot be
 calculated

Signed-off-by: Ilija Puaca <ilija@unfolded.ai>
---
 src/components/geocoder-panel.js   | 13 ++++++-------
 src/components/plot-container.js   | 26 +++++++++-----------------
 src/reducers/map-state-updaters.js | 19 +++++++++----------
 3 files changed, 24 insertions(+), 34 deletions(-)

diff --git a/src/components/geocoder-panel.js b/src/components/geocoder-panel.js
index d0143ceac1..25ed6bb6ca 100644
--- a/src/components/geocoder-panel.js
+++ b/src/components/geocoder-panel.js
@@ -135,18 +135,17 @@ export default function GeocoderPanelFactory() {
         lon + GEOCODER_GEO_OFFSET,
         lat + GEOCODER_GEO_OFFSET
       ];
-      const {zoom} = geoViewport.viewport(bounds, [
+      const centerAndZoom = geoViewport.viewport(bounds, [
         this.props.mapState.width,
         this.props.mapState.height
       ]);
-      // center being calculated by geo-vieweport.viewport has a complex logic that
-      // projects and then unprojects the coordinates to determine the center
-      // Calculating a simple average instead as that is the expected behavior in most of cases
-      const center = [(bounds[0] + bounds[2]) / 2, (bounds[1] + bounds[3]) / 2];
 
       this.props.updateMap({
-        latitude: center[1],
-        longitude: center[0],
+        latitude: centerAndZoom.center[1],
+        longitude: centerAndZoom.center[0],
+        // For marginal or invalid bounds, zoom may be NaN. Make sure to provide a valid value in order
+        // to avoid corrupt state and potential crashes as zoom is expected to be a number
+        ...(Number.isFinite(centerAndZoom.zoom) ? {zoom: centerAndZoom.zoom} : {}),
         zoom,
         pitch: 0,
         bearing: 0,
diff --git a/src/components/plot-container.js b/src/components/plot-container.js
index 0c0639df7f..c428bac021 100644
--- a/src/components/plot-container.js
+++ b/src/components/plot-container.js
@@ -173,23 +173,15 @@ export default function PlotContainerFactory(MapContainer) {
       };
 
       if (exportImageSetting.center) {
-        const getViewport = shouldCenter => {
-          if (shouldCenter) {
-            const {zoom} = geoViewport.viewport(bounds, [width, height]);
-            // center being calculated by geo-vieweport.viewport has a complex logic that
-            // projects and then unprojects the coordinates to determine the center
-            // Calculating a simple average instead as that is the expected behavior in most of cases
-            const center = [(bounds[0] + bounds[2]) / 2, (bounds[1] + bounds[3]) / 2];
-            return {center, zoom};
-          }
-
-          return {center: [mapState.longitude, mapState.latitude], zoom: mapState.zoom};
-        };
-
-        const {center, zoom} = getViewport(exportImageSetting.center);
-
-        newMapState.longitude = center[0];
-        newMapState.latitude = center[1];
+        const viewport = exportImageSetting.center
+          ? geoViewport.viewport(bounds, [width, height])
+          : {center: [newMapState.longitude, newMapState.latitude], zoom: mapState.zoom};
+        // For marginal or invalid bounds, zoom may be NaN. Make sure to provide a valid value in order
+        // to avoid corrupt state and potential crashes as zoom is expected to be a number
+        const zoom = viewport.zoom || mapState.zoom;
+
+        newMapState.longitude = viewport.center[0];
+        newMapState.latitude = viewport.center[1];
         newMapState.zoom = zoom + Number(Math.log2(scale) || 0);
       }
 
diff --git a/src/reducers/map-state-updaters.js b/src/reducers/map-state-updaters.js
index 96fed7595a..b6c33c7c67 100644
--- a/src/reducers/map-state-updaters.js
+++ b/src/reducers/map-state-updaters.js
@@ -113,20 +113,19 @@ export const updateMapUpdater = (state, action) => ({
 export const fitBoundsUpdater = (state, action) => {
   const bounds = validateBounds(action.payload);
   if (!bounds) {
-    Console.warn('invalid map bounds provided')
+    Console.warn('invalid map bounds provided');
     return state;
-  }  
-  const {zoom} = geoViewport.viewport(bounds, [state.width, state.height]);
-  // center being calculated by geo-vieweport.viewport has a complex logic that
-  // projects and then unprojects the coordinates to determine the center
-  // Calculating a simple average instead as that is the expected behavior in most of cases
-  const center = [(bounds[0] + bounds[2]) / 2, (bounds[1] + bounds[3]) / 2];
+  }
+
+  const viewport = geoViewport.viewport(bounds, [state.width, state.height]);
 
   return {
     ...state,
-    latitude: center[1],
-    longitude: center[0],
-    zoom
+    latitude: viewport.center[1],
+    longitude: viewport.center[0],
+    // For marginal or invalid bounds, zoom may be NaN. Make sure to provide a valid value in order
+    // to avoid corrupt state and potential crashes as zoom is expected to be a number
+    ...(Number.isFinite(viewport.zoom) ? {zoom: viewport.zoom} : {})
   };
 };