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+// NOTICE!! DO NOT USE ANY OF THIS JAVASCRIPT
+// IT'S JUST JUNK FOR OUR DOCS!
+// ++++++++++++++++++++++++++++++++++++++++++
+/*!
+ * Copyright 2014-2019 Twitter, Inc.
+ *
+ * Licensed under the Creative Commons Attribution 3.0 Unported License. For
+ * details, see https://creativecommons.org/licenses/by/3.0/.
+ */
+// Intended to prevent false-positive bug reports about Bootstrap not working properly in old versions of IE due to folks testing using IE's unreliable emulation modes.
+(function () {
+ 'use strict';
+
+ function emulatedIEMajorVersion() {
+ var groups = /MSIE ([0-9.]+)/.exec(window.navigator.userAgent)
+ if (groups === null) {
+ return null
+ }
+ var ieVersionNum = parseInt(groups[1], 10)
+ var ieMajorVersion = Math.floor(ieVersionNum)
+ return ieMajorVersion
+ }
+
+ function actualNonEmulatedIEMajorVersion() {
+ // Detects the actual version of IE in use, even if it's in an older-IE emulation mode.
+ // IE JavaScript conditional compilation docs: https://msdn.microsoft.com/library/121hztk3%28v=vs.94%29.aspx
+ // @cc_on docs: https://msdn.microsoft.com/library/8ka90k2e%28v=vs.94%29.aspx
+ var jscriptVersion = new Function('/*@cc_on return @_jscript_version; @*/')() // jshint ignore:line
+ if (jscriptVersion === undefined) {
+ return 11 // IE11+ not in emulation mode
+ }
+ if (jscriptVersion < 9) {
+ return 8 // IE8 (or lower; haven't tested on IE<8)
+ }
+ return jscriptVersion // IE9 or IE10 in any mode, or IE11 in non-IE11 mode
+ }
+
+ var ua = window.navigator.userAgent
+ if (ua.indexOf('Opera') > -1 || ua.indexOf('Presto') > -1) {
+ return // Opera, which might pretend to be IE
+ }
+ var emulated = emulatedIEMajorVersion()
+ if (emulated === null) {
+ return // Not IE
+ }
+ var nonEmulated = actualNonEmulatedIEMajorVersion()
+
+ if (emulated !== nonEmulated) {
+ window.alert('WARNING: You appear to be using IE' + nonEmulated + ' in IE' + emulated + ' emulation mode.\nIE emulation modes can behave significantly differently from ACTUAL older versions of IE.\nPLEASE DON\'T FILE BOOTSTRAP BUGS based on testing in IE emulation modes!')
+ }
+})();