Revert "Fix for race condition in readystate detection (#1972)"

This reverts commit 78a9ecf.

src/htmx.js

@@ -3752,34 +3752,25 @@ return (function () {
         //====================================================================
         // Initialization
         //====================================================================
+        var isReady = false
+        getDocument().addEventListener('DOMContentLoaded', function() {
+            isReady = true
+        })
+
         /**
-         * We want to initialize the page elements after DOMContentLoaded
-         * fires, but there isn't always a good way to tell whether
-         * it has already fired when we get here or not.
+         * Execute a function now if DOMContentLoaded has fired, otherwise listen for it.
+         *
+         * This function uses isReady because there is no realiable way to ask the browswer whether
+         * the DOMContentLoaded event has already been fired; there's a gap between DOMContentLoaded
+         * firing and readystate=complete.
          */
-        function ready(functionToCall) {
-            // call the function exactly once no matter how many times this is called
-            var callReadyFunction = function() {
-                if (!functionToCall) return;
-                functionToCall();
-                functionToCall = null;
-            };
-
-            if (getDocument().readyState === "complete") {
-                // DOMContentLoaded definitely fired, we can initialize the page
-                callReadyFunction();
-            }
-            else {
-                /* DOMContentLoaded *maybe* already fired, wait for
-                 * the next DOMContentLoaded or readystatechange event
-                 */
-                getDocument().addEventListener("DOMContentLoaded", function() {
-                    callReadyFunction();
-                });
-                getDocument().addEventListener("readystatechange", function() {
-                    if (getDocument().readyState !== "complete") return;
-                    callReadyFunction();
-                });
+        function ready(fn) {
+            // Checking readyState here is a failsafe in case the htmx script tag entered the DOM by
+            // some means other than the initial page load.
+            if (isReady || getDocument().readyState === 'complete') {
+                fn();
+            } else {
+                getDocument().addEventListener('DOMContentLoaded', fn);
             }
         }