Fix HTML5 history in IE11 (and hopefully others)

closest method is not available in IE, but we only need to find ancestor
by tag name which is easy and relatively fast anyway.

modules/reitit-frontend/src/reitit/frontend/history.cljs

@@ -49,6 +49,16 @@
     (if path
       (str "#" path))))
 
+(defn- closest-by-tag [el tag]
+  ;; nodeName is upper case for HTML always,
+  ;; for XML or XHTML it would be in the original case.
+  (let [tag (.toUpperCase tag)]
+    (loop [el el]
+    (if el
+      (if (= tag (.-nodeName el))
+        el
+        (recur (.-parentNode el)))))))
+
 (defrecord Html5History [on-navigate router listen-key click-listen-key]
   History
   (-init [this]
@@ -66,7 +76,7 @@
           (fn ignore-anchor-click
             [e]
             ;; Returns the next matching anchestor of event target
-            (when-let [el (.closest (.-target e) "a")]
+            (when-let [el (closest-by-tag (.-target e) "a")]
               (let [uri (.parse Uri (.-href el))]
                 (when (and (or (and (not (.hasScheme uri)) (not (.hasDomain uri)))
                                (= current-domain (.getDomain uri)))
@@ -79,7 +89,7 @@
                            (= 0 (.-button e))
                            ;; isContentEditable property is inherited from parents,
                            ;; so if the anchor is inside contenteditable div, the property will be true.
-                           (not (.-isContentEditable (.-target e)))
+                           (not (.-isContentEditable el))
                            (reitit/match-by-path router (.getPath uri)))
                   (.preventDefault e)
                   (let [path (str (.getPath uri)