Make sure we always process inlines as whitespace significant

src/Avalonia.Controls/Documents/InlineCollection.cs

@@ -92,12 +92,46 @@ namespace Avalonia.Controls.Documents
         /// <param name="text"></param>
         public void Add(string text)
         {
-            Add(new Run(text));
+            AddText(text);
+        }
+
+        public override void Add(Inline inline)
+        {
+            OnAdd();
+
+            base.Add(inline);
         }
 
         public void Add(IControl child)
         {
-            Add(new InlineUIContainer(child));
+            OnAdd();
+
+            base.Add(new InlineUIContainer(child));
+        }
+
+        private void AddText(string text)
+        {
+            if(Parent is RichTextBlock textBlock && !textBlock.HasComplexContent)
+            {
+                textBlock._text += text;
+            }
+            else
+            {
+                base.Add(new Run(text));
+            }
+        }
+
+        private void OnAdd()
+        {
+            if (Parent is RichTextBlock textBlock)
+            {
+                if (!textBlock.HasComplexContent && !string.IsNullOrEmpty(textBlock._text))
+                {
+                    base.Add(new Run(textBlock._text));
+
+                    textBlock._text = null;
+                }
+            }
         }
 
         /// <summary>

src/Avalonia.Controls/Documents/Span.cs

@@ -1,4 +1,3 @@
-using System;
 using System.Collections.Generic;
 using System.Text;
 using Avalonia.Media.TextFormatting;

src/Avalonia.Controls/RichTextBlock.cs

@@ -16,7 +16,7 @@ namespace Avalonia.Controls
     /// <summary>
     /// A control that displays a block of formatted text.
     /// </summary>
-    public class RichTextBlock : TextBlock, IInlineHost, IAddChild<string>, IAddChild<Inline>, IAddChild<IControl>
+    public class RichTextBlock : TextBlock, IInlineHost
     {
         public static readonly StyledProperty<bool> IsTextSelectionEnabledProperty =
             AvaloniaProperty.Register<RichTextBlock, bool>(nameof(IsTextSelectionEnabled), false);
@@ -148,6 +148,7 @@ namespace Avalonia.Controls
         /// <summary>
         /// Gets or sets the inlines.
         /// </summary>
+        [Content]
         public InlineCollection Inlines
         {
             get => GetValue(InlinesProperty);
@@ -252,35 +253,6 @@ namespace Avalonia.Controls
             SelectionEnd = SelectionStart;
         }
 
-        void IAddChild<string>.AddChild(string text)
-        {
-            AddText(text);
-        }
-
-        void IAddChild<Inline>.AddChild(Inline inline)
-        {
-            if (!HasComplexContent && !string.IsNullOrEmpty(_text))
-            {
-                Inlines.Add(_text);
-
-                _text = null;
-            }
-
-            Inlines.Add(inline);
-        }
-
-        void IAddChild<IControl>.AddChild(IControl child)
-        {
-            if (!HasComplexContent && !string.IsNullOrEmpty(_text))
-            {
-                Inlines.Add(_text);
-
-                _text = null;
-            }
-
-            Inlines.Add(new InlineUIContainer(child));
-        }
-
         protected void AddText(string? text)
         {
             if (string.IsNullOrEmpty(text))

src/Avalonia.Controls/TextBlock.cs

@@ -129,7 +129,7 @@ namespace Avalonia.Controls
         public static readonly StyledProperty<TextDecorationCollection?> TextDecorationsProperty =
             AvaloniaProperty.Register<TextBlock, TextDecorationCollection?>(nameof(TextDecorations));
 
-        protected string? _text;
+        internal string? _text;
         protected TextLayout? _textLayout;
         protected Size _constraint;
 

src/Markup/Avalonia.Markup.Xaml.Loader/xamlil.github

@@ -1 +1 @@
-Subproject commit a4e6be2d1407abec4f35fcb208848830ce513ead
+Subproject commit d990d63774a04d2a4b3d52e626a90ee68e19e2b6