fix: Escapes location search results

Nominatim results were inserted via innerHTML and loaded as a JSONP script
with an unencoded query. Results are now fetched as JSON, the query is URL
encoded, text is escaped and coordinates must be numeric.

web/www/sunders/js/search.js

@@ -37,15 +37,32 @@ function searchLocation(maxResults) {
       searchLimit = 11;
     }
 
-    var searchScript = document.createElement('script');
-    searchScript.src = 'https://nominatim.openstreetmap.org/search.php?q=' + searchString + '&format=json&json_callback=parseResult&limit=' + searchLimit;
-    document.body.appendChild(searchScript);
+    var searchUrl = 'https://nominatim.openstreetmap.org/search?q=' + encodeURIComponent(searchString)
+      + '&format=json&limit=' + encodeURIComponent(searchLimit);
+    fetch(searchUrl)
+      .then(function(response) { return response.json(); })
+      .then(parseResult)
+      .catch(function() { parseResult([]); });
   }
 }
 
+// Escape a value for use in HTML text and in double-quoted attributes.
+function escapeSearchHtml(value) {
+  return String(value)
+    .replace(/&/g, '&')
+    .replace(/</g, '&lt;')
+    .replace(/>/g, '&gt;')
+    .replace(/"/g, '&quot;')
+    .replace(/'/g, '&#39;');
+}
+
 function parseResult(response) {
   var searchResultDivs = '';
 
+  if (!Array.isArray(response)) {
+    response = [];
+  }
+
   if (response.length == searchLimit) {
     var lastResultIndex = searchLimit - 1;
     var nextSearchLimit = searchLimit + 10;
@@ -67,10 +84,15 @@ function parseResult(response) {
   // Show the current 10 search results.
   for (var i=searchLimit-11; i<lastResultIndex; i++) {
     searchResult = response[i];
+    var lat = Number(searchResult.lat);
+    var lon = Number(searchResult.lon);
+    if (!isFinite(lat) || !isFinite(lon)) {
+      continue;
+    }
     searchResultDivs +=
-      '<div class="search-result" onClick="gotoLocation(' + searchResult.lat + ', ' + searchResult.lon + ');return false;">' +
-        '<div class="text-medium">' + searchResult.class + ' / ' + searchResult.type + '</div>' +
-        '<div>' + searchResult.display_name + '</div>' +
+      '<div class="search-result" onClick="gotoLocation(' + lat + ', ' + lon + ');return false;">' +
+        '<div class="text-medium">' + escapeSearchHtml(searchResult.class) + ' / ' + escapeSearchHtml(searchResult.type) + '</div>' +
+        '<div>' + escapeSearchHtml(searchResult.display_name) + '</div>' +
       '</div>';
   }