fix: deterministic GPX ordering in parseGpxFiles (trip.html.twig)

themes/intotheeast/templates/trip.html.twig

@@ -405,35 +405,42 @@ function haversineKm(lat1, lng1, lat2, lng2) {
 
 function parseGpxFiles(urls, callback) {
     var pending = urls.length;
-    var masterPts = [];
+    var fileResults = new Array(urls.length);
     if (pending === 0) { callback({ error: 'no files' }); return; }
-    urls.forEach(function(url) {
+    urls.forEach(function(url, idx) {
         fetch(url)
             .then(function(r) { return r.text(); })
             .then(function(text) {
                 var xml = new DOMParser().parseFromString(text, 'text/xml');
                 var trkpts = xml.querySelectorAll('trkpt');
+                var pts = [];
                 trkpts.forEach(function(pt) {
                     var eleEl = pt.querySelector('ele');
                     var timeEl = pt.querySelector('time');
-                    masterPts.push({
+                    pts.push({
                         lat: parseFloat(pt.getAttribute('lat')),
                         lon: parseFloat(pt.getAttribute('lon')),
                         ele: eleEl ? parseFloat(eleEl.textContent) : NaN,
                         time: timeEl ? timeEl.textContent : null
                     });
                 });
+                fileResults[idx] = pts;
                 pending--;
                 if (pending === 0) { computeAndCallback(); }
             })
             .catch(function(err) {
                 console.warn('GPX load failed:', url, err);
+                fileResults[idx] = [];
                 pending--;
                 if (pending === 0) { computeAndCallback(); }
             });
     });
 
     function computeAndCallback() {
+        var masterPts = [];
+        fileResults.forEach(function(pts) {
+            if (pts) { pts.forEach(function(p) { masterPts.push(p); }); }
+        });
         var n = masterPts.length;
         if (n < 2) { callback({ distance: 0 }); return; }
         var distance = 0, eleGain = 0, eleLoss = 0;