MSHTML IHTMLTxtRange.pasteHtml() and FEATURE_BROWSER_EMULATION=11001 = wrong html

Question

If I enable emulation of IE11 for my application in registry here:
HKCU\Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION\myAppName.exe
and insert html into WinForms WebBrowser control using function IHTMLTxtRange.pasteHtml(), then text between html elements is interpreted probably wrong:
-spaces transformed to <p> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p>
-line breaks between html elements transformed to <br/> tags.
As a result I get wrong html.
Test application:
Form1.cs:
public partial class Form1 : Form
        public Form1()
            //enable IE11 mode
            string fileName = System.IO.Path.GetFileName(Process.GetCurrentProcess().MainModule.FileName);
            using (RegistryKey key = Registry.CurrentUser.CreateSubKey(
                @"Software\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BROWSER_EMULATION",
                RegistryKeyPermissionCheck.ReadWriteSubTree))
                key.SetValue(fileName, (UInt32)11001, RegistryValueKind.DWord);
            InitializeComponent();
        private void button1_Click(object sender, EventArgs e)
            //enable design mode
            webBrowser1.Navigate("about:blank");
            IHTMLDocument2 mshtmlDoc2 = webBrowser1.Document.DomDocument as IHTMLDocument2;
            mshtmlDoc2.designMode = "On";
            //insert html
            while (mshtmlDoc2.readyState != "complete")
                Application.DoEvents();
            mshtmlDoc2.body.innerHTML = "<p>paragraph 1</p>";
            IHTMLTxtRange bodyRange = (mshtmlDoc2.body as IHTMLBodyElement).createTextRange();
            bodyRange.collapse(Start: false);
            bodyRange.pasteHTML("<p>paragraph 2</p>\n\n\n        <p>paragraph 3</p>");
            //show result html
            textBox1.Text = webBrowser1.DocumentText;
Form1.designer.cs:
partial class Form1
        /// <summary>
        /// Required designer variable.
        /// </summary>
        private System.ComponentModel.IContainer components = null;
        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
            if (disposing && (components != null))
                components.Dispose();
            base.Dispose(disposing);
        #region Windows Form Designer generated code
        /// <summary>
        /// Required method for Designer support - do not modify
        /// the contents of this method with the code editor.
        /// </summary>
        private void InitializeComponent()
            this.webBrowser1 = new System.Windows.Forms.WebBrowser();
            this.button1 = new System.Windows.Forms.Button();
            this.textBox1 = new System.Windows.Forms.TextBox();
            this.SuspendLayout();
            // webBrowser1
            this.webBrowser1.Location = new System.Drawing.Point(12, 12);
            this.webBrowser1.MinimumSize = new System.Drawing.Size(20, 20);
            this.webBrowser1.Name = "webBrowser1";
            this.webBrowser1.Size = new System.Drawing.Size(626, 190);
            this.webBrowser1.TabIndex = 0;
            // button1
            this.button1.Location = new System.Drawing.Point(12, 338);
            this.button1.Name = "button1";
            this.button1.Size = new System.Drawing.Size(143, 23);
            this.button1.TabIndex = 1;
            this.button1.Text = "Insert html";
            this.button1.UseVisualStyleBackColor = true;
            this.button1.Click += new System.EventHandler(this.button1_Click);
            // textBox1
            this.textBox1.Location = new System.Drawing.Point(12, 208);
            this.textBox1.Multiline = true;
            this.textBox1.Name = "textBox1";
            this.textBox1.Size = new System.Drawing.Size(626, 124);
            this.textBox1.TabIndex = 2;
            // Form1
            this.AutoScaleDimensions = new System.Drawing.SizeF(6F, 13F);
            this.AutoScaleMode = System.Windows.Forms.AutoScaleMode.Font;
            this.ClientSize = new System.Drawing.Size(652, 373);
            this.Controls.Add(this.textBox1);
            this.Controls.Add(this.button1);
            this.Controls.Add(this.webBrowser1);
            this.Name = "Form1";
            this.Text = "Form1";
            this.ResumeLayout(false);
            this.PerformLayout();
        #endregion
        private System.Windows.Forms.WebBrowser webBrowser1;
        private System.Windows.Forms.Button button1;
        private System.Windows.Forms.TextBox textBox1;
As a result I get the following html which, I think, is wrong:
<P>paragraph 1</P>
<P>paragraph 2</P>
<P><BR><BR><BR>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; </P>
<P>paragraph 3</P>

Answer 1

Hi,
remove the exogenous whitespace from your markup strings. IE10 and later support textnodes.
is whitespace (space+NL)
"&nbsp;<br/>" is the markup equivalent
<elm>
 <span>content<span>
</elm>
document.queryselector('elm').firstChild.nodeName
#textnode
is not the same as
<elm><span>content</span></elm>
document.queryselector('elm').firstChild.nodeName
SPAN
In the Developer tool of webkit browsers you can turn on whitespace formatter to display the control characters (white space) that is in the source markup.
Make sure your web pages contain a utf-8 content-type meta
<meta content="text/html; charset=utf-8" http-equiv="Content-Type">
Rob^_^