From b7ae04bdbaeff0a23bbd71a6a5af3dc900cf2b2c Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20G=C3=B6ls?=
 <6608231+Abrynos@users.noreply.github.com>
Date: Mon, 18 Mar 2024 09:04:47 +0100
Subject: [PATCH] Make alert block headers case-invariant

---
 src/Markdig/Extensions/Alerts/AlertBlockRenderer.cs    | 4 +++-
 src/Markdig/Extensions/Alerts/AlertInlineParser.cs     | 4 ++--
 src/Markdig/Extensions/Bootstrap/BootstrapExtension.cs | 5 ++++-
 3 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/src/Markdig/Extensions/Alerts/AlertBlockRenderer.cs b/src/Markdig/Extensions/Alerts/AlertBlockRenderer.cs
index f9b95d61..1309f568 100644
--- a/src/Markdig/Extensions/Alerts/AlertBlockRenderer.cs
+++ b/src/Markdig/Extensions/Alerts/AlertBlockRenderer.cs
@@ -61,7 +61,9 @@ public class AlertBlockRenderer : HtmlObjectRenderer<AlertBlock>
     /// <param name="kind">The kind of the alert to render</param>
     public static void DefaultRenderKind(HtmlRenderer renderer, StringSlice kind)
     {
-        string? html = kind.AsSpan() switch
+        Span<char> upperKind = stackalloc char[kind.Length];
+        kind.AsSpan().ToUpperInvariant(upperKind);
+        string? html = upperKind switch
         {
             "NOTE" => "<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M0 8a8 8 0 1 1 16 0A8 8 0 0 1 0 8Zm8-6.5a6.5 6.5 0 1 0 0 13 6.5 6.5 0 0 0 0-13ZM6.5 7.75A.75.75 0 0 1 7.25 7h1a.75.75 0 0 1 .75.75v2.75h.25a.75.75 0 0 1 0 1.5h-2a.75.75 0 0 1 0-1.5h.25v-2h-.25a.75.75 0 0 1-.75-.75ZM8 6a1 1 0 1 1 0-2 1 1 0 0 1 0 2Z\"></path></svg>Note</p>",
             "TIP" => "<p class=\"markdown-alert-title\"><svg viewBox=\"0 0 16 16\" version=\"1.1\" width=\"16\" height=\"16\" aria-hidden=\"true\"><path d=\"M8 1.5c-2.363 0-4 1.69-4 3.75 0 .984.424 1.625.984 2.304l.214.253c.223.264.47.556.673.848.284.411.537.896.621 1.49a.75.75 0 0 1-1.484.211c-.04-.282-.163-.547-.37-.847a8.456 8.456 0 0 0-.542-.68c-.084-.1-.173-.205-.268-.32C3.201 7.75 2.5 6.766 2.5 5.25 2.5 2.31 4.863 0 8 0s5.5 2.31 5.5 5.25c0 1.516-.701 2.5-1.328 3.259-.095.115-.184.22-.268.319-.207.245-.383.453-.541.681-.208.3-.33.565-.37.847a.751.751 0 0 1-1.485-.212c.084-.593.337-1.078.621-1.489.203-.292.45-.584.673-.848.075-.088.147-.173.213-.253.561-.679.985-1.32.985-2.304 0-2.06-1.637-3.75-4-3.75ZM5.75 12h4.5a.75.75 0 0 1 0 1.5h-4.5a.75.75 0 0 1 0-1.5ZM6 15.25a.75.75 0 0 1 .75-.75h2.5a.75.75 0 0 1 0 1.5h-2.5a.75.75 0 0 1-.75-.75Z\"></path></svg>Tip</p>",
diff --git a/src/Markdig/Extensions/Alerts/AlertInlineParser.cs b/src/Markdig/Extensions/Alerts/AlertInlineParser.cs
index f5a5881d..6f95c5b6 100644
--- a/src/Markdig/Extensions/Alerts/AlertInlineParser.cs
+++ b/src/Markdig/Extensions/Alerts/AlertInlineParser.cs
@@ -46,7 +46,7 @@ public class AlertInlineParser : InlineParser
 
         var start = slice.Start;
         var end = start;
-        while (c.IsAlphaUpper())
+        while (c.IsAlpha())
         {
             end = slice.Start;
             c = slice.NextChar();
@@ -86,7 +86,7 @@ public class AlertInlineParser : InlineParser
                 }
                 break;
             }
-            else if (!c.IsSpaceOrTab()) 
+            else if (!c.IsSpaceOrTab())
             {
                 slice = saved;
                 return false;
diff --git a/src/Markdig/Extensions/Bootstrap/BootstrapExtension.cs b/src/Markdig/Extensions/Bootstrap/BootstrapExtension.cs
index 560cc7bf..483377bb 100644
--- a/src/Markdig/Extensions/Bootstrap/BootstrapExtension.cs
+++ b/src/Markdig/Extensions/Bootstrap/BootstrapExtension.cs
@@ -61,7 +61,10 @@ public class BootstrapExtension : IMarkdownExtension
                     var attributes = node.GetAttributes();
                     attributes.AddClass("alert");
                     attributes.AddProperty("role", "alert");
-                    string? @class = alertBlock.Kind.AsSpan() switch
+
+                    Span<char> upperKind = new char[alertBlock.Kind.Length];
+                    alertBlock.Kind.AsSpan().ToUpperInvariant(upperKind);
+                    string? @class = upperKind switch
                     {
                         "NOTE" => "alert-primary",
                         "TIP" => "alert-success",