Fixing structure issue of nested lists indented by tabs (#2172) (#2173)

Author: alexgarbarev

pkgs/markdown/CHANGELOG.md

@@ -6,6 +6,7 @@
 * Fix performance and correctness of HTML comment parser.
 * Optimize indentation processing of fenced code blocks.
 * Require Dart `^3.4.0`.
+* Fix an issue with nested list structure when indented by tabs (#2172).
 
 ## 7.3.0
 

pkgs/markdown/lib/src/block_syntaxes/list_syntax.dart

@@ -211,7 +211,9 @@ abstract class ListSyntax extends BlockSyntax {
           // any indentation past the required whitespace character.
           indent = precedingWhitespaces;
         } else {
-          indent = precedingWhitespaces + contentWhitespances;
+          indent = precedingWhitespaces +
+              contentWhitespances +
+              (parser.current.tabRemaining ?? 0);
         }
 
         taskListItemState = null;

pkgs/markdown/test/original/unordered_lists.unit

@@ -118,6 +118,26 @@ two</li>
 
 * two
 
+<<<
+<ul>
+<li>
+<p>one</p>
+<ul>
+<li>nested one</li>
+<li>nested two</li>
+</ul>
+</li>
+<li>
+<p>two</p>
+</li>
+</ul>
+>>> can nest lists by tabs
+* one
+	* nested one
+	* nested two
+
+* two
+
 <<<
 <ul>
 <li>
@@ -149,3 +169,58 @@ item</li>
 <li>list</li>
 </ul>
 <hr />
+>>> can nest multiple levels with tabs.
+- Level 1, 1
+- Level 1, 2
+	- Level 2, 1
+	- Level 2, 2
+		- Level 3, 1
+		- Level 3, 2
+		- Level 3, 3
+			- Level 4, 1
+			- Level 4, 2
+			- Level 4, 3
+				- Level 5, 1
+				- Level 5, 2
+				- Level 5, 3
+				- Level 5, 4
+					- Level 6, 1
+					- Level 6, 2
+					- Level 6, 3
+- Level 1, 4
+<<<
+<ul>
+<li>Level 1, 1</li>
+<li>Level 1, 2
+<ul>
+<li>Level 2, 1</li>
+<li>Level 2, 2
+<ul>
+<li>Level 3, 1</li>
+<li>Level 3, 2</li>
+<li>Level 3, 3
+<ul>
+<li>Level 4, 1</li>
+<li>Level 4, 2</li>
+<li>Level 4, 3
+<ul>
+<li>Level 5, 1</li>
+<li>Level 5, 2</li>
+<li>Level 5, 3</li>
+<li>Level 5, 4
+<ul>
+<li>Level 6, 1</li>
+<li>Level 6, 2</li>
+<li>Level 6, 3</li>
+</ul>
+</li>
+</ul>
+</li>
+</ul>
+</li>
+</ul>
+</li>
+</ul>
+</li>
+<li>Level 1, 4</li>
+</ul>