Merge pull request webpack#8467 from Connormiha/simplify-append-head

Use document.head instead of getElementsByTagName('head')

Author: sokra

lib/web/JsonpMainTemplate.runtime.js

@@ -12,12 +12,11 @@ module.exports = function() {
 
 	// eslint-disable-next-line no-unused-vars
 	function hotDownloadUpdateChunk(chunkId) {
-		var head = document.getElementsByTagName("head")[0];
 		var script = document.createElement("script");
 		script.charset = "utf-8";
 		script.src = $require$.p + $hotChunkFilename$;
 		if ($crossOriginLoading$) script.crossOrigin = $crossOriginLoading$;
-		head.appendChild(script);
+		document.head.appendChild(script);
 	}
 
 	// eslint-disable-next-line no-unused-vars

lib/web/JsonpMainTemplatePlugin.js

@@ -282,9 +282,8 @@ class JsonpMainTemplatePlugin {
 							"promises.push(installedChunkData[2] = promise);",
 							"",
 							"// start chunk loading",
-							"var head = document.getElementsByTagName('head')[0];",
 							mainTemplate.hooks.jsonpScript.call("", chunk, hash),
-							"head.appendChild(script);"
+							"document.head.appendChild(script);"
 						]),
 						"}"
 					]),
@@ -310,14 +309,13 @@ class JsonpMainTemplatePlugin {
 					"var chunkPreloadData = chunkPreloadMap[chunkId];",
 					"if(chunkPreloadData) {",
 					Template.indent([
-						"var head = document.getElementsByTagName('head')[0];",
 						"chunkPreloadData.forEach(function(chunkId) {",
 						Template.indent([
 							"if(installedChunks[chunkId] === undefined) {",
 							Template.indent([
 								"installedChunks[chunkId] = null;",
 								mainTemplate.hooks.linkPreload.call("", chunk, hash),
-								"head.appendChild(link);"
+								"document.head.appendChild(link);"
 							]),
 							"}"
 						]),
@@ -388,14 +386,13 @@ class JsonpMainTemplatePlugin {
 							withPrefetch
 								? Template.asString([
 										"// chunk prefetching for javascript",
-										"var head = document.getElementsByTagName('head')[0];",
 										"prefetchChunks.forEach(function(chunkId) {",
 										Template.indent([
 											"if(installedChunks[chunkId] === undefined) {",
 											Template.indent([
 												"installedChunks[chunkId] = null;",
 												mainTemplate.hooks.linkPrefetch.call("", chunk, hash),
-												"head.appendChild(link);"
+												"document.head.appendChild(link);"
 											]),
 											"}"
 										]),