footnotes: Fix multiple paragraphs separated by blank lines

Author: robinst

CHANGELOG.md

@@ -6,6 +6,12 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/).
 This project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html),
 with the exception that 0.x versions can break between minor versions.
 
+## Unreleased
+### Fixed
+- footnotes: Fix parsing of footnote definitions containing multiple paragraphs
+  separated by blank lines. Before it only worked if paragraphs were separated
+  by lines of 4 spaces. (#388)
+
 ## [0.25.0] - 2025-06-20
 ### Added
 - Include OSGi metadata in jars (`META-INF/MANIFEST.MF` files) (#378)

commonmark-ext-footnotes/src/main/java/org/commonmark/ext/footnotes/internal/FootnoteBlockParser.java

@@ -39,6 +39,10 @@ public BlockContinue tryContinue(ParserState parserState) {
         if (parserState.getIndent() >= 4) {
             // It looks like content needs to be indented by 4 so that it's part of a footnote (instead of starting a new block).
             return BlockContinue.atColumn(4);
+        } else if (parserState.isBlank()) {
+            // A blank line doesn't finish a footnote yet. If there's another line with indent >= 4 after it,
+            // that should result in another paragraph in this footnote definition.
+            return BlockContinue.atIndex(parserState.getIndex());
         } else {
             // We're not continuing to give other block parsers a chance to interrupt this definition.
             // But if no other block parser applied (including another FootnotesBlockParser), we will

commonmark-ext-footnotes/src/main/java/org/commonmark/ext/footnotes/internal/FootnoteMarkdownNodeRenderer.java

@@ -55,9 +55,7 @@ private void renderDefinition(FootnoteDefinition def) {
         writer.raw("]: ");
 
         writer.pushPrefix("    ");
-        writer.pushTight(true);
         renderChildren(def);
-        writer.popTight();
         writer.popPrefix();
     }
 

commonmark-ext-footnotes/src/test/java/org/commonmark/ext/footnotes/FootnoteMarkdownRendererTest.java

@@ -23,7 +23,7 @@ public void testSimple() {
     @Test
     public void testUnreferenced() {
         // Whether a reference has a corresponding definition or vice versa shouldn't matter for Markdown rendering.
-        assertRoundTrip("Test [^foo]\n\n[^foo]: one\n[^bar]: two\n");
+        assertRoundTrip("Test [^foo]\n\n[^foo]: one\n\n[^bar]: two\n");
     }
 
     @Test
@@ -36,6 +36,18 @@ public void testBackslashInLabel() {
         assertRoundTrip("[^\\foo]\n\n[^\\foo]: note\n");
     }
 
+    @Test
+    public void testMultipleLines() {
+        assertRoundTrip("Test [^1]\n\n[^1]: footnote l1\n    footnote l2\n");
+    }
+
+    @Test
+    public void testMultipleParagraphs() {
+        // Note that the line between p1 and p2 could be blank too (instead of 4 spaces), but we currently don't
+        // preserve that information.
+        assertRoundTrip("Test [^1]\n\n[^1]: footnote p1\n    \n    footnote p2\n");
+    }
+
     @Test
     public void testInline() {
         assertRoundTrip("^[test *foo*]\n");

commonmark-ext-footnotes/src/test/java/org/commonmark/ext/footnotes/FootnotesTest.java

@@ -102,6 +102,26 @@ public void testDefContainsMultipleLines() {
         assertText("still", paragraph.getLastChild());
     }
 
+    @Test
+    public void testDefContainsMultipleParagraphs() {
+        var doc = PARSER.parse("[^1]: footnote p1\n\n    footnote p2\n");
+        var def = find(doc, FootnoteDefinition.class);
+        assertThat(def.getLabel()).isEqualTo("1");
+        var p1 = (Paragraph) def.getFirstChild();
+        assertText("footnote p1", p1.getFirstChild());
+        var p2 = (Paragraph) p1.getNext();
+        assertText("footnote p2", p2.getFirstChild());
+    }
+
+    @Test
+    public void testDefFollowedByParagraph() {
+        var doc = PARSER.parse("[^1]: footnote\n\nnormal paragraph\n");
+        var def = find(doc, FootnoteDefinition.class);
+        assertThat(def.getLabel()).isEqualTo("1");
+        assertText("footnote", def.getFirstChild().getFirstChild());
+        assertText("normal paragraph", def.getNext().getFirstChild());
+    }
+
     @Test
     public void testDefContainsList() {
         var doc = PARSER.parse("[^1]: - foo\n    - bar\n");

commonmark-integration-test/pom.xml

@@ -20,6 +20,10 @@
             <groupId>org.commonmark</groupId>
             <artifactId>commonmark-ext-autolink</artifactId>
         </dependency>
+        <dependency>
+            <groupId>org.commonmark</groupId>
+            <artifactId>commonmark-ext-footnotes</artifactId>
+        </dependency>
         <dependency>
             <groupId>org.commonmark</groupId>
             <artifactId>commonmark-ext-ins</artifactId>

commonmark-integration-test/src/test/java/org/commonmark/integration/Extensions.java

@@ -2,6 +2,7 @@
 
 import org.commonmark.Extension;
 import org.commonmark.ext.autolink.AutolinkExtension;
+import org.commonmark.ext.footnotes.FootnotesExtension;
 import org.commonmark.ext.front.matter.YamlFrontMatterExtension;
 import org.commonmark.ext.gfm.strikethrough.StrikethroughExtension;
 import org.commonmark.ext.gfm.tables.TablesExtension;
@@ -15,6 +16,7 @@ public class Extensions {
 
     static final List<Extension> ALL_EXTENSIONS = List.of(
             AutolinkExtension.create(),
+            FootnotesExtension.create(),
             ImageAttributesExtension.create(),
             InsExtension.create(),
             StrikethroughExtension.create(),

commonmark-integration-test/src/test/java/org/commonmark/integration/MarkdownRendererIntegrationTest.java

@@ -18,16 +18,8 @@
 
 public class MarkdownRendererIntegrationTest {
 
-    private static final List<Extension> EXTENSIONS = List.of(
-            AutolinkExtension.create(),
-            ImageAttributesExtension.create(),
-            InsExtension.create(),
-            StrikethroughExtension.create(),
-            TablesExtension.create(),
-            TaskListItemsExtension.create(),
-            YamlFrontMatterExtension.create());
-    private static final Parser PARSER = Parser.builder().extensions(EXTENSIONS).build();
-    private static final MarkdownRenderer RENDERER = MarkdownRenderer.builder().extensions(EXTENSIONS).build();
+    private static final Parser PARSER = Parser.builder().extensions(Extensions.ALL_EXTENSIONS).build();
+    private static final MarkdownRenderer RENDERER = MarkdownRenderer.builder().extensions(Extensions.ALL_EXTENSIONS).build();
 
     @Test
     public void testStrikethroughInTable() {

pom.xml

@@ -139,6 +139,11 @@
                 <artifactId>commonmark-ext-autolink</artifactId>
                 <version>0.25.1-SNAPSHOT</version>
             </dependency>
+            <dependency>
+                <groupId>org.commonmark</groupId>
+                <artifactId>commonmark-ext-footnotes</artifactId>
+                <version>0.25.1-SNAPSHOT</version>
+            </dependency>
             <dependency>
                 <groupId>org.commonmark</groupId>
                 <artifactId>commonmark-ext-image-attributes</artifactId>