fix(markdown_parser): restore leading-space stripping after hard line breaks

crates/biome_markdown_parser/src/syntax/mod.rs

@@ -858,6 +858,12 @@ fn is_quote_blank_line_after_newline(p: &mut MarkdownParser, quote_depth: usize)
 
     p.lookahead(|p| {
         p.bump(NEWLINE);
+        is_quote_blank_line_from_current(p, quote_depth)
+    })
+}
+
+fn is_quote_blank_line_from_current(p: &mut MarkdownParser, quote_depth: usize) -> bool {
+    p.lookahead(|p| {
         if is_quote_only_blank_line_from_source(p, quote_depth) {
             return true;
         }
@@ -1009,8 +1015,22 @@ fn handle_inline_newline(p: &mut MarkdownParser, has_content: bool) -> InlineNew
     // Consume the NEWLINE as textual content (remap to MD_TEXTUAL_LITERAL)
     emit_inline_newline_as_text(p);
 
-    // If we're inside a block quote, only consume the quote prefix
-    // when it doesn't start a new block (e.g., a nested quote).
+    handle_line_continuation(p, has_content, true)
+}
+
+/// Consume container continuation prefixes and check for block interrupts.
+///
+/// Called after a line boundary has been crossed — either a NEWLINE (via
+/// `handle_inline_newline`) or a hard line break (`MD_HARD_LINE_LITERAL`,
+/// which embeds its own newline). Handles quote prefixes, list indent,
+/// setext underlines, and other block-level constructs that can end or
+/// interrupt a paragraph.
+fn handle_line_continuation(
+    p: &mut MarkdownParser,
+    has_content: bool,
+    emit_indent_tokens: bool,
+) -> InlineNewlineAction {
+    let quote_depth = p.state().block_quote_depth;
     if break_for_quote_prefix_after_inline_newline(p, quote_depth) {
         return InlineNewlineAction::Break;
     }
@@ -1024,12 +1044,6 @@ fn handle_inline_newline(p: &mut MarkdownParser, has_content: bool) -> InlineNew
         return InlineNewlineAction::Break;
     }
 
-    // Inside a nested list item (depth >= 2), break the paragraph when the
-    // continuation line's indent drops to or below the marker column.
-    // Such lines belong to a parent item, not lazy continuation.
-    // We only check nesting depth, not marker_indent alone, because a
-    // top-level list with leading whitespace (e.g. `  1.  text`) still
-    // allows lazy continuation at indent 0 per CommonMark §5.2.
     if required_indent > 0 && p.state().list_nesting_depth >= 2 {
         let marker_indent = p.state().list_item_marker_indent;
         if marker_indent > 0 {
@@ -1040,9 +1054,6 @@ fn handle_inline_newline(p: &mut MarkdownParser, has_content: bool) -> InlineNew
         }
     }
 
-    // Check for block-level constructs that can interrupt paragraphs.
-    // Textual fence tokens (e.g. "```") may not be caught by line_starts_with_fence
-    // because the lexer emits them as MD_TEXTUAL_LITERAL in inline context.
     if p.at(MD_TEXTUAL_LITERAL) {
         let text = p.cur_text();
         if text.starts_with("```") || text.starts_with("~~~") {
@@ -1053,7 +1064,9 @@ fn handle_inline_newline(p: &mut MarkdownParser, has_content: bool) -> InlineNew
         return InlineNewlineAction::Break;
     }
 
-    emit_inline_continuation_indent(p, required_indent);
+    if emit_indent_tokens {
+        emit_inline_continuation_indent(p, required_indent);
+    }
 
     InlineNewlineAction::Continue
 }
@@ -1145,8 +1158,21 @@ pub(crate) fn parse_inline_item_list(p: &mut MarkdownParser) {
         after_hard_break = matches!(&parsed, Present(cm) if cm.kind(p) == MD_HARD_LINE);
 
         // Per CommonMark §6.7: after a hard line break, leading spaces on the
-        // next line are ignored. Consume as whitespace trivia (structural).
+        // next line are ignored. First, run container continuation handling so
+        // block quote/list prefixes remain part of the same paragraph.
         if after_hard_break {
+            let quote_depth = p.state().block_quote_depth;
+            if p.at(NEWLINE) || is_quote_blank_line_from_current(p, quote_depth) {
+                break;
+            }
+
+            if matches!(
+                handle_line_continuation(p, has_content, false),
+                InlineNewlineAction::Break
+            ) {
+                break;
+            }
+
             while p.at(MD_TEXTUAL_LITERAL) && p.cur_text().chars().all(|c| c == ' ' || c == '\t') {
                 p.consume_as_whitespace_trivia();
             }

crates/biome_markdown_parser/src/to_html.rs

@@ -2007,6 +2007,36 @@ mod tests {
         assert_eq!(html, "<p>foo\\</p>\n");
     }
 
+    #[test]
+    fn test_hard_break_in_blockquote() {
+        let parsed = parse_markdown("> foo  \n> bar  \n>\n> baz");
+        let html = document_to_html(
+            &parsed.tree(),
+            parsed.list_tightness(),
+            parsed.list_item_indents(),
+            parsed.quote_indents(),
+        );
+        assert_eq!(
+            html,
+            "<blockquote>\n<p>foo<br />\nbar</p>\n<p>baz</p>\n</blockquote>\n"
+        );
+    }
+
+    #[test]
+    fn test_hard_break_nested_quote_in_list() {
+        let parsed = parse_markdown("- > quoted  \n  > line  \n  >\n  > next para\n\n- after\n");
+        let html = document_to_html(
+            &parsed.tree(),
+            parsed.list_tightness(),
+            parsed.list_item_indents(),
+            parsed.quote_indents(),
+        );
+        assert_eq!(
+            html,
+            "<ul>\n<li>\n<blockquote>\n<p>quoted<br />\nline</p>\n<p>next para</p>\n</blockquote>\n</li>\n<li>\n<p>after</p>\n</li>\n</ul>\n"
+        );
+    }
+
     #[test]
     fn test_tight_list_marker_split() {
         // Two tight lists separated by blank line with different markers

crates/biome_markdown_parser/tests/md_test_suite/ok/hard_break_in_blockquote.md

@@ -0,0 +1,4 @@
+> foo  
+> bar  
+>
+> baz

crates/biome_markdown_parser/tests/md_test_suite/ok/hard_break_in_blockquote.md.snap

@@ -0,0 +1,123 @@
+---
+source: crates/biome_markdown_parser/tests/spec_test.rs
+expression: snapshot
+---
+
+## Input
+
+```
+> foo  
+> bar  
+>
+> baz
+```
+
+
+## AST
+
+```
+MdDocument {
+    bom_token: missing (optional),
+    value: MdBlockList [
+        MdQuote {
+            prefix: MdQuotePrefix {
+                pre_marker_indent: MdQuoteIndentList [],
+                marker_token: R_ANGLE@0..1 ">" [] [],
+                post_marker_space_token: MD_QUOTE_POST_MARKER_SPACE@1..2 " " [] [],
+            },
+            content: MdBlockList [
+                MdParagraph {
+                    list: MdInlineItemList [
+                        MdTextual {
+                            value_token: MD_TEXTUAL_LITERAL@2..5 "foo" [] [],
+                        },
+                        MdHardLine {
+                            value_token: MD_HARD_LINE_LITERAL@5..8 "  \n" [] [],
+                        },
+                        MdQuotePrefix {
+                            pre_marker_indent: MdQuoteIndentList [],
+                            marker_token: R_ANGLE@8..9 ">" [] [],
+                            post_marker_space_token: MD_QUOTE_POST_MARKER_SPACE@9..10 " " [] [],
+                        },
+                        MdTextual {
+                            value_token: MD_TEXTUAL_LITERAL@10..13 "bar" [] [],
+                        },
+                        MdHardLine {
+                            value_token: MD_HARD_LINE_LITERAL@13..16 "  \n" [] [],
+                        },
+                    ],
+                    hard_line: missing (optional),
+                },
+                MdQuotePrefix {
+                    pre_marker_indent: MdQuoteIndentList [],
+                    marker_token: R_ANGLE@16..17 ">" [] [],
+                    post_marker_space_token: missing (optional),
+                },
+                MdNewline {
+                    value_token: NEWLINE@17..18 "\n" [] [],
+                },
+                MdQuotePrefix {
+                    pre_marker_indent: MdQuoteIndentList [],
+                    marker_token: R_ANGLE@18..19 ">" [] [],
+                    post_marker_space_token: MD_QUOTE_POST_MARKER_SPACE@19..20 " " [] [],
+                },
+                MdParagraph {
+                    list: MdInlineItemList [
+                        MdTextual {
+                            value_token: MD_TEXTUAL_LITERAL@20..23 "baz" [] [],
+                        },
+                    ],
+                    hard_line: missing (optional),
+                },
+            ],
+        },
+    ],
+    eof_token: EOF@23..23 "" [] [],
+}
+```
+
+## CST
+
+```
+0: MD_DOCUMENT@0..23
+  0: (empty)
+  1: MD_BLOCK_LIST@0..23
+    0: MD_QUOTE@0..23
+      0: MD_QUOTE_PREFIX@0..2
+        0: MD_QUOTE_INDENT_LIST@0..0
+        1: R_ANGLE@0..1 ">" [] []
+        2: MD_QUOTE_POST_MARKER_SPACE@1..2 " " [] []
+      1: MD_BLOCK_LIST@2..23
+        0: MD_PARAGRAPH@2..16
+          0: MD_INLINE_ITEM_LIST@2..16
+            0: MD_TEXTUAL@2..5
+              0: MD_TEXTUAL_LITERAL@2..5 "foo" [] []
+            1: MD_HARD_LINE@5..8
+              0: MD_HARD_LINE_LITERAL@5..8 "  \n" [] []
+            2: MD_QUOTE_PREFIX@8..10
+              0: MD_QUOTE_INDENT_LIST@8..8
+              1: R_ANGLE@8..9 ">" [] []
+              2: MD_QUOTE_POST_MARKER_SPACE@9..10 " " [] []
+            3: MD_TEXTUAL@10..13
+              0: MD_TEXTUAL_LITERAL@10..13 "bar" [] []
+            4: MD_HARD_LINE@13..16
+              0: MD_HARD_LINE_LITERAL@13..16 "  \n" [] []
+          1: (empty)
+        1: MD_QUOTE_PREFIX@16..17
+          0: MD_QUOTE_INDENT_LIST@16..16
+          1: R_ANGLE@16..17 ">" [] []
+          2: (empty)
+        2: MD_NEWLINE@17..18
+          0: NEWLINE@17..18 "\n" [] []
+        3: MD_QUOTE_PREFIX@18..20
+          0: MD_QUOTE_INDENT_LIST@18..18
+          1: R_ANGLE@18..19 ">" [] []
+          2: MD_QUOTE_POST_MARKER_SPACE@19..20 " " [] []
+        4: MD_PARAGRAPH@20..23
+          0: MD_INLINE_ITEM_LIST@20..23
+            0: MD_TEXTUAL@20..23
+              0: MD_TEXTUAL_LITERAL@20..23 "baz" [] []
+          1: (empty)
+  2: EOF@23..23 "" [] []
+
+```

crates/biome_markdown_parser/tests/md_test_suite/ok/hard_break_in_list_item.md

@@ -0,0 +1,6 @@
+- foo  
+  bar  
+
+  baz
+
+- simple