fix: two missed Markdown splits and table rows

src/parser/markdown.rs

@@ -1342,9 +1342,10 @@ fn list_remainder_raw_end(lines: &[Line<'_>], start: usize, rest: &str) -> Optio
     if header.len() != dcells.len() || !dcells.iter().all(|c| is_gfm_delimiter_cell(c)) {
         return None;
     }
+    let header_indent = line_indent(delim.text);
     let mut end = start + 1;
     for (j, line) in lines.iter().enumerate().skip(start + 2) {
-        if !is_gfm_table_row(line.text) {
+        if !continues_gfm_table(line.text, header_indent) {
             break;
         }
         end = j;
@@ -1490,7 +1491,7 @@ fn quoted_gfm_table_end(lines: &[Line<'_>], start: usize, depth: usize) -> Optio
         let Some(inner) = strip_quote_markers(line.text, depth) else {
             break;
         };
-        if !is_gfm_table_row(inner) {
+        if !continues_gfm_table(inner, line_indent(header_inner)) {
             break;
         }
         end = j;
@@ -1741,6 +1742,32 @@ fn is_gfm_table_row(line: &str) -> bool {
     gfm_table_cells(line).is_some()
 }
 
+/// A line that continues a GFM table body although it has no pipe.
+/// The table runs to a blank line or a block that interrupts a paragraph
+/// (GFM ex. 202; pulldown `parse_table_row`), so `bar` under the last row
+/// is one more row, not prose.
+/// A line indented less than the header may belong to an outer container,
+/// so it ends the table here and stays prose.
+fn is_gfm_lazy_table_row(line: &str, min_indent: usize) -> bool {
+    let content = line.trim_start();
+    if content.is_empty() || line_indent(line) < min_indent {
+        return false;
+    }
+    !(is_thematic_break(content)
+        || HEADING_RE.is_match(content)
+        || FENCED_CODE_RE.is_match(content)
+        || content.starts_with('>')
+        || LIST_ITEM_RE.is_match(content)
+        || html_block_kind(content).is_some_and(HtmlBlock::can_interrupt)
+        || is_footnote_definition(content))
+}
+
+/// True when `line` is the next row of a GFM table whose header is indented
+/// by `header_indent`.
+fn continues_gfm_table(line: &str, header_indent: usize) -> bool {
+    is_gfm_table_row(line) || is_gfm_lazy_table_row(line, header_indent)
+}
+
 /// Pandoc line block: a line that starts with `|` and a space, and does
 /// not end with a pipe. A flanking-pipe row is a table ([`TABLE_ROW_RE`]),
 /// not a line block. `|cell` (no space) is prose.
@@ -1765,9 +1792,10 @@ fn gfm_table_end(lines: &[Line<'_>], start: usize) -> Option<usize> {
     if header.len() != dcells.len() || !dcells.iter().all(|c| is_gfm_delimiter_cell(c)) {
         return None;
     }
+    let header_indent = line_indent(lines[start].text);
     let mut end = start + 1;
     for (j, line) in lines.iter().enumerate().skip(start + 2) {
-        if !is_gfm_table_row(line.text) {
+        if !continues_gfm_table(line.text, header_indent) {
             break;
         }
         end = j;

src/sentence/unicode.rs

@@ -3873,7 +3873,7 @@ fn glue_tick_capital_after_punct(result: &mut Vec<String>, segment: &str) -> boo
 
 fn merge_splits_inside_delimiters(segments: Vec<String>) -> Vec<String> {
     let mut result: Vec<String> = Vec::with_capacity(segments.len());
-    let mut state = DelimState::default();
+    let mut state = DelimState::for_text(&segments.concat());
 
     for segment in segments {
         if state.is_inside() {
@@ -3979,9 +3979,28 @@ pub struct DelimState {
     last_char: Option<char>,
     /// When the previous chunk ended in `\`, the next `"` / `'` is escaped.
     pending_escape: bool,
+    /// LaTeX `''` closers still ahead in the text, when known.
+    /// A ```` with no `''` left to close it is literal, as an unmatched
+    /// backtick run is in CommonMark, so it opens no span.
+    latex_closers_ahead: Option<i32>,
 }
 
 impl DelimState {
+    /// A state that knows how many `''` closers `text` holds, so a
+    /// ```` with none left after it stays literal.
+    pub fn for_text(text: &str) -> Self {
+        let mut probe = DelimState {
+            latex_closers_ahead: Some(0),
+            ..DelimState::default()
+        };
+        probe.feed(text);
+        let closers = -probe.latex_closers_ahead.unwrap_or(0);
+        DelimState {
+            latex_closers_ahead: Some(closers),
+            ..DelimState::default()
+        }
+    }
+
     pub fn is_inside(&self) -> bool {
         self.ascii_double_open
             || self.ascii_single_open
@@ -4023,12 +4042,20 @@ impl DelimState {
                     self.last_char = Some('`');
                     continue;
                 }
-                self.latex_quote_depth += 1;
+                if self
+                    .latex_closers_ahead
+                    .is_none_or(|ahead| ahead > self.latex_quote_depth)
+                {
+                    self.latex_quote_depth += 1;
+                }
                 self.last_char = Some('`');
                 continue;
             }
             if ch == '\'' && next == Some('\'') {
                 let _ = iter.next();
+                if let Some(ahead) = self.latex_closers_ahead.as_mut() {
+                    *ahead -= 1;
+                }
                 self.latex_quote_depth = (self.latex_quote_depth - 1).max(0);
                 self.last_char = Some('\'');
                 continue;
@@ -4124,7 +4151,7 @@ pub fn newlines_respect_delimiter_spans(formatted: &str) -> bool {
         return true;
     }
     let (protected, _) = protect_inline_tokens(trimmed_end);
-    let mut state = DelimState::default();
+    let mut state = DelimState::for_text(&protected);
     for line in protected.split('\n') {
         if state.is_inside() {
             return false;

tests/integration.rs

@@ -54,6 +54,8 @@ mod md_example_list;
 mod md_four_space_nested_list;
 #[path = "md_gfm_alerts.rs"]
 mod md_gfm_alerts;
+#[path = "md_gfm_table_lazy_rows.rs"]
+mod md_gfm_table_lazy_rows;
 #[path = "md_html_comment_indent.rs"]
 mod md_html_comment_indent;
 #[path = "md_html_type6_close.rs"]
@@ -108,6 +110,8 @@ mod md_ref_link_interior_punct;
 mod md_shortcut_ref_label;
 #[path = "md_spanning_lrd_title.rs"]
 mod md_spanning_lrd_title;
+#[path = "md_unclosed_double_backtick.rs"]
+mod md_unclosed_double_backtick;
 #[path = "md_yaml_front_matter.rs"]
 mod md_yaml_front_matter;
 #[path = "org_angle_links.rs"]

tests/md_gfm_table_lazy_rows.rs

@@ -0,0 +1,67 @@
+//! A GFM table runs to a blank line or a block that interrupts a paragraph
+//! (GFM ex. 202). A line under the last row with no pipe is one more row,
+//! so splitting it would add a row. A list, heading or outer line after the
+//! table still splits.
+
+use snapper_fmt::format::Format;
+use snapper_fmt::{FormatConfig, format_text};
+
+fn md_cfg() -> FormatConfig {
+    FormatConfig {
+        format: Format::Markdown,
+        max_width: 0,
+        ..Default::default()
+    }
+    .without_safety_backstops()
+}
+
+fn fmt(input: &str) -> String {
+    let out = format_text(input, &md_cfg()).unwrap();
+    assert_eq!(format_text(&out, &md_cfg()).unwrap(), out, "not idempotent");
+    out
+}
+
+#[test]
+fn line_under_the_last_row_stays_a_row() {
+    let input = "| a | b |\n|---|---|\n| x | y |\nAfter table. Next.\n\nOne here. Two here.\n";
+    let out = fmt(input);
+    assert!(
+        out.contains("| x | y |\nAfter table. Next.\n"),
+        "a pipe-less line under the table is a row, got:\n{out}"
+    );
+    assert!(
+        out.contains("One here.\nTwo here.\n"),
+        "the paragraph after the blank line must still split, got:\n{out}"
+    );
+}
+
+#[test]
+fn list_or_heading_after_the_table_still_splits() {
+    let input = "| a | b |\n|---|---|\n| x | y |\n- Item one. Item two.\n\n\
+                 | a | b |\n|---|---|\n| x | y |\n# Head\nPara one. Para two.\n";
+    let out = fmt(input);
+    assert!(
+        out.contains("- Item one.\n  Item two.\n"),
+        "a list item ends the table, got:\n{out}"
+    );
+    assert!(
+        out.contains("# Head\nPara one.\nPara two.\n"),
+        "a heading ends the table, got:\n{out}"
+    );
+}
+
+#[test]
+fn quoted_table_keeps_its_lazy_row() {
+    let input = "> | q | w |\n> |---|---|\n> | e | t |\n> lazy quoted. Row too.\n";
+    assert_eq!(fmt(input), input);
+}
+
+#[test]
+fn outer_line_after_a_list_item_table_still_splits() {
+    let input = "- item\n\n  | k | v |\n  |---|---|\n  | p | r |\nOuter line. Second one.\n";
+    let out = fmt(input);
+    assert!(
+        out.contains("  | p | r |\nOuter line.\nSecond one.\n"),
+        "a line outside the list item is not a row, got:\n{out}"
+    );
+}

tests/md_light_table_interrupt.rs

@@ -69,6 +69,8 @@ fn heavy_table_still_interrupts() {
         "| alpha. | bravo. |\n",
         "| --- | --- |\n",
         "After. Next.\n",
+        "\n",
+        "One more. Last one.\n",
     );
     let regions = MarkdownParser.parse(input);
     assert!(
@@ -79,8 +81,13 @@ fn heavy_table_still_interrupts() {
         "heavy table must still interrupt, got {regions:?}"
     );
     let out = format_text(input, &md_cfg()).unwrap();
+    // GFM ex. 202: the line under the delimiter row is a body row.
     assert!(
-        out.contains("After.\nNext."),
-        "following prose must still split, got:\n{out}"
+        out.contains("| --- | --- |\nAfter. Next.\n"),
+        "the pipe-less line under the table is a row, got:\n{out}"
+    );
+    assert!(
+        out.contains("One more.\nLast one."),
+        "prose after the blank line must still split, got:\n{out}"
     );
 }

tests/md_unclosed_double_backtick.rs

@@ -0,0 +1,50 @@
+//! A ```` with no `''` after it is literal, as an unmatched backtick run
+//! is in CommonMark. It must not hold the rest of the paragraph on one line.
+//! A closed LaTeX quote still keeps its sentences together.
+
+use snapper_fmt::format::Format;
+use snapper_fmt::{FormatConfig, format_text};
+
+fn cfg(format: Format) -> FormatConfig {
+    FormatConfig {
+        format,
+        max_width: 0,
+        ..Default::default()
+    }
+    .without_safety_backstops()
+}
+
+#[test]
+fn unclosed_double_backtick_does_not_stop_splits() {
+    let input = "Unclosed `` tick here. Next sentence. Third one.\n";
+    let out = format_text(input, &cfg(Format::Markdown)).unwrap();
+    assert_eq!(
+        out, "Unclosed `` tick here.\nNext sentence.\nThird one.\n",
+        "an unmatched `` must not open a span, got:\n{out}"
+    );
+    assert_eq!(format_text(&out, &cfg(Format::Markdown)).unwrap(), out);
+}
+
+#[test]
+fn unclosed_double_backtick_after_a_closed_quote_still_splits() {
+    let input = "He said ``Stop. Now.'' and left. Then `` stray. Next one.\n";
+    let out = format_text(input, &cfg(Format::Plaintext)).unwrap();
+    assert!(
+        out.contains("``Stop. Now.''"),
+        "a closed LaTeX quote must stay one span, got:\n{out}"
+    );
+    assert!(
+        out.contains("stray.\nNext one.\n"),
+        "the unmatched `` after it must not open a span, got:\n{out}"
+    );
+}
+
+#[test]
+fn closed_latex_quote_stays_whole() {
+    let input = "He said ``Stop. Now.'' and left. Next sentence.\n";
+    let out = format_text(input, &cfg(Format::Latex)).unwrap();
+    assert!(
+        out.contains("``Stop. Now.'' and left.\nNext sentence.\n"),
+        "a closed LaTeX quote must stay one span, got:\n{out}"
+    );
+}