Unobtrusively support the breaking up of ordered lists without resetting their indices/steps

CHANGELOG.md

@@ -1,5 +1,13 @@
 # Changelog
 
+## Version 4.0.0
+
+* Unobtrusively support the breaking up of ordered lists without resetting their indices/steps.
+
+  Fixes #740.
+
+  *Dennis Hackethal*
+
 ## Version 3.6.0
 
 * Avoid warnings running on Ruby 3.2+.

README.markdown

@@ -254,7 +254,7 @@ end
 * header(text, header_level)
 * hrule()
 * list(contents, list_type)
-* list_item(text, list_type)
+* list_item(text, list_type, step)
 * paragraph(text)
 * table(header, body)
 * table_row(content)

ext/redcarpet/html.c

@@ -404,9 +404,14 @@ rndr_list(struct buf *ob, const struct buf *text, int flags, void *opaque)
 }
 
 static void
-rndr_listitem(struct buf *ob, const struct buf *text, int flags, void *opaque)
+rndr_listitem(struct buf *ob, const struct buf *text, int flags, void *opaque, int step)
 {
-	BUFPUTSL(ob, "<li>");
+	if (flags & MKD_LIST_ORDERED) {
+		bufprintf(ob, "<li data-step=\"%d\">", step);
+	} else {
+		BUFPUTSL(ob, "<li>");
+	}
+
 	if (text) {
 		size_t size = text->size;
 		while (size && text->data[size - 1] == '\n')

ext/redcarpet/markdown.c

@@ -1848,6 +1848,24 @@ parse_blockcode(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t
 	return beg;
 }
 
+/* extract_prefix_number • Extracts '12' from '12. foo' */
+/* Useful for list items of ordered lists */
+static int
+extract_prefix_number(uint8_t *data, size_t size)
+{
+	size_t i = 0;
+	int prefix_num = 0;
+
+	while (i < size && data[i] == ' ') i++;
+
+	while (i < size && data[i] >= '0' && data[i] <= '9') {
+		prefix_num = prefix_num * 10 + (data[i] - '0');
+		i++;
+	}
+
+	return prefix_num;
+}
+
 /* parse_listitem • parsing of a single list item */
 /*	assuming initial prefix is already removed */
 static size_t
@@ -1862,13 +1880,17 @@ parse_listitem(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t s
 	while (orgpre < 3 && orgpre < size && data[orgpre] == ' ')
 		orgpre++;
 
+	int prefix_num = 0;
+
 	beg = prefix_uli(data, size);
 	if (!beg)
 		beg = prefix_oli(data, size);
 
 	if (!beg)
 		return 0;
 
+	prefix_num = extract_prefix_number(data, size);
+
 	/* skipping to the beginning of the following line */
 	end = beg;
 	while (end < size && data[end - 1] != '\n')
@@ -1977,7 +1999,7 @@ parse_listitem(struct buf *ob, struct sd_markdown *rndr, uint8_t *data, size_t s
 
 	/* render of li itself */
 	if (rndr->cb.listitem)
-		rndr->cb.listitem(ob, inter, *flags, rndr->opaque);
+		rndr->cb.listitem(ob, inter, *flags, rndr->opaque, prefix_num);
 
 	rndr_popbuf(rndr, BUFFER_SPAN);
 	rndr_popbuf(rndr, BUFFER_SPAN);

ext/redcarpet/markdown.h

@@ -75,7 +75,7 @@ struct sd_callbacks {
 	void (*header)(struct buf *ob, const struct buf *text, int level, void *opaque);
 	void (*hrule)(struct buf *ob, void *opaque);
 	void (*list)(struct buf *ob, const struct buf *text, int flags, void *opaque);
-	void (*listitem)(struct buf *ob, const struct buf *text, int flags, void *opaque);
+	void (*listitem)(struct buf *ob, const struct buf *text, int flags, void *opaque, int step);
 	void (*paragraph)(struct buf *ob, const struct buf *text, void *opaque);
 	void (*table)(struct buf *ob, const struct buf *header, const struct buf *body, void *opaque);
 	void (*table_row)(struct buf *ob, const struct buf *text, void *opaque);

ext/redcarpet/rc_render.c

@@ -86,10 +86,10 @@ rndr_list(struct buf *ob, const struct buf *text, int flags, void *opaque)
 }
 
 static void
-rndr_listitem(struct buf *ob, const struct buf *text, int flags, void *opaque)
+rndr_listitem(struct buf *ob, const struct buf *text, int flags, void *opaque, int step)
 {
-	BLOCK_CALLBACK("list_item", 2, buf2str(text),
-			(flags & MKD_LIST_ORDERED) ? CSTR2SYM("ordered") : CSTR2SYM("unordered"));
+	BLOCK_CALLBACK("list_item", 3, buf2str(text),
+			(flags & MKD_LIST_ORDERED) ? CSTR2SYM("ordered") : CSTR2SYM("unordered"), INT2NUM(step));
 }
 
 static void

lib/redcarpet.rb

@@ -2,7 +2,7 @@
 require 'redcarpet/compat'
 
 module Redcarpet
-  VERSION = '3.6.0'
+  VERSION = '4.0.0'
 
   class Markdown
     attr_reader :renderer

lib/redcarpet/render_man.rb

@@ -52,10 +52,10 @@ def list(content, list_type)
         end
       end
 
-      def list_item(content, list_type)
+      def list_item(content, list_type, step)
         case list_type
         when :ordered
-          ".IP \\n+[step]\n#{content.strip}\n"
+          ".IP \\n+[#{step}]\n#{content.strip}\n"
         when :unordered
           ".IP \\[bu] 2 \n#{content.strip}\n"
         end

redcarpet.gemspec

@@ -1,10 +1,10 @@
 # encoding: utf-8
 Gem::Specification.new do |s|
   s.name = 'redcarpet'
-  s.version = '3.6.0'
+  s.version = '4.0.0'
   s.summary = "Markdown that smells nice"
   s.description = 'A fast, safe and extensible Markdown to (X)HTML parser'
-  s.date = '2023-01-29'
+  s.date = '2023-08-25'
   s.email = 'vicent@github.com'
   s.homepage = 'https://github.com/vmg/redcarpet'
   s.authors = ["Natacha Porté", "Vicent Martí"]

test/MarkdownTest_1.0.3/Tests/Ordered and unordered lists.html

@@ -57,44 +57,52 @@ <h2>Ordered</h2>
 <p>Tight:</p>
 
 <ol>
-<li>First</li>
-<li>Second</li>
-<li>Third</li>
+<li data-step="1">First</li>
+<li data-step="2">Second</li>
+<li data-step="3">Third</li>
 </ol>
 
 <p>and:</p>
 
 <ol>
-<li>One</li>
-<li>Two</li>
-<li>Three</li>
+<li data-step="1">One</li>
+<li data-step="2">Two</li>
+<li data-step="3">Three</li>
 </ol>
 
 <p>Loose using tabs:</p>
 
 <ol>
-<li><p>First</p></li>
-<li><p>Second</p></li>
-<li><p>Third</p></li>
+<li data-step="1"><p>First</p></li>
+<li data-step="2"><p>Second</p></li>
+<li data-step="3"><p>Third</p></li>
 </ol>
 
 <p>and using spaces:</p>
 
 <ol>
-<li><p>One</p></li>
-<li><p>Two</p></li>
-<li><p>Three</p></li>
+<li data-step="1"><p>One</p></li>
+<li data-step="2"><p>Two</p></li>
+<li data-step="3"><p>Three</p></li>
 </ol>
 
 <p>Multiple paragraphs:</p>
 
 <ol>
-<li><p>Item 1, graf one.</p>
+<li data-step="1"><p>Item 1, graf one.</p>
 
 <p>Item 2. graf two. The quick brown fox jumped over the lazy dog's
 back.</p></li>
-<li><p>Item 2.</p></li>
-<li><p>Item 3.</p></li>
+<li data-step="2"><p>Item 2.</p></li>
+<li data-step="3"><p>Item 3.</p></li>
+</ol>
+
+<p>Custom steps:</p>
+
+<ol>
+<li data-step="2">Two</li>
+<li data-step="5">Five</li>
+<li data-step="13">Thirteen</li>
 </ol>
 
 <h2>Nested</h2>
@@ -112,28 +120,28 @@ <h2>Nested</h2>
 <p>Here's another:</p>
 
 <ol>
-<li>First</li>
-<li>Second:
+<li data-step="1">First</li>
+<li data-step="2">Second:
 <ul>
 <li>Fee</li>
 <li>Fie</li>
 <li>Foe</li>
 </ul></li>
-<li>Third</li>
+<li data-step="3">Third</li>
 </ol>
 
 <p>Same thing but with paragraphs:</p>
 
 <ol>
-<li><p>First</p></li>
-<li><p>Second:</p>
+<li data-step="1"><p>First</p></li>
+<li data-step="2"><p>Second:</p>
 
 <ul>
 <li>Fee</li>
 <li>Fie</li>
 <li>Foe</li>
 </ul></li>
-<li><p>Third</p></li>
+<li data-step="3"><p>Third</p></li>
 </ol>
 
 
@@ -146,3 +154,26 @@ <h2>Nested</h2>
 
 <p>that</p></li>
 </ul>
+
+<p>Nested custom steps:</p>
+<ol>
+<li data-step="1">First</li>
+<li data-step="2">Second
+<ol>
+<li data-step="5">Nested fifth</li>
+<li data-step="7">Nested seventh</li>
+</ol>
+</li>
+<li data-step="3">Third</li>
+</ol>
+
+<p>Nested custom steps within unordered:</p>
+<ul>
+<li>Foo
+<ol>
+<li data-step="3">Nested third</li>
+<li data-step="7">Nested seventh</li>
+</ol>
+</li>
+<li>Bar</li>
+</ul>

test/MarkdownTest_1.0.3/Tests/Ordered and unordered lists.text

@@ -93,7 +93,11 @@ Multiple paragraphs:
 
 3.	Item 3.
 
+Custom steps:
 
+2. Two
+5. Five
+13. Thirteen
 
 ## Nested
 
@@ -129,3 +133,18 @@ This was an error in Markdown 1.0.1:
 	*	sub
 
 	that
+
+Nested custom steps:
+
+1. First
+2. Second
+	5. Nested fifth
+	7. Nested seventh
+3. Third
+
+Nested custom steps within unordered:
+
+* Foo
+	3. Nested third
+	7. Nested seventh
+* Bar

test/markdown_test.rb

@@ -398,8 +398,23 @@ def test_char_escaping_when_highlighting
   def test_ordered_lists_with_lax_spacing
     output = render("Foo:\n1. Foo\n2. Bar", with: [:lax_spacing])
 
-    assert_match /<ol>/, output
-    assert_match /<li>Foo<\/li>/, output
+    assert_equal %{<p>Foo:</p>
+
+<ol>
+<li data-step="1">Foo</li>
+<li data-step="2">Bar</li>
+</ol>}, output
+  end
+
+  def test_ordered_lists_with_lax_spacing_and_custom_start
+    output = render("Foo:\n2. Foo\n5. Bar", with: [:lax_spacing])
+
+    assert_equal %{<p>Foo:</p>
+
+<ol>
+<li data-step="2">Foo</li>
+<li data-step="5">Bar</li>
+</ol>}, output
   end
 
   def test_references_with_tabs_after_colon