Fix drawer parsing to not take headlines

src/elements/drawer.rs

@@ -7,7 +7,10 @@ use nom::{
     IResult,
 };
 
-use crate::parse::combinators::{blank_lines_count, eol, lines_till};
+use crate::{
+    parse::combinators::{blank_lines_count, eol, lines_till},
+    parsers::lines_until_headline_at_level_le,
+};
 
 /// Drawer Element
 #[derive(Debug, Default, Clone)]
@@ -59,7 +62,18 @@ pub fn parse_drawer_without_blank(input: &str) -> IResult<&str, (Drawer, &str),
         tag(":"),
     )(input)?;
     let (input, _) = eol(input)?;
-    let (input, contents) = lines_till(|line| line.trim().eq_ignore_ascii_case(":END:"))(input)?;
+
+    // Restrict the search for the end of the drawer to the current headline.
+    let (_input_after_headline, (input_until_headline, _level)) =
+        lines_until_headline_at_level_le(input, std::usize::MAX)?;
+
+    // tail is the remaining not used for the drawer out of
+    // input_until_headline.
+    let (tail, contents) =
+        lines_till(|line| line.trim().eq_ignore_ascii_case(":END:"))(input_until_headline)?;
+
+    // Skip over the amount used by the drawer.
+    let input = &input[input_until_headline.len() - tail.len()..];
 
     Ok((
         input,
@@ -118,4 +132,30 @@ fn parse() {
 
     // https://github.com/PoiScript/orgize/issues/9
     assert!(parse_drawer(":SPAGHETTI:\n").is_err());
+
+    // https://github.com/PoiScript/orgize/issues/24
+    // A drawer may not contain a headline.
+    assert!(parse_drawer(
+        r#":MYDRAWER:
+* Node
+  :END:"#
+    )
+    .is_err(),);
+
+    // A drawer may not contain another drawer. An attempt to do so will result
+    // in the drawer ending at the first end line.
+    assert_eq!(
+        parse_drawer(":OUTER:\nOuter Text\n:INNER:\nInner Text\n:END:\n:END:"),
+        Ok((
+            ":END:",
+            (
+                Drawer {
+                    name: "OUTER".into(),
+                    pre_blank: 0,
+                    post_blank: 0
+                },
+                "Outer Text\n:INNER:\nInner Text\n"
+            )
+        ))
+    );
 }

src/elements/title.rs

@@ -453,5 +453,5 @@ fn parse_properties_drawer_() {
                 .into_iter()
                 .collect::<HashMap<_, _>>()
         ))
-    )
+    );
 }

src/parsers.rs

@@ -4,7 +4,12 @@ use std::marker::PhantomData;
 use indextree::{Arena, NodeId};
 use jetscii::{bytes, BytesConst};
 use memchr::{memchr, memchr_iter};
-use nom::bytes::complete::take_while1;
+use nom::{
+    bytes::complete::is_a,
+    character::complete::one_of,
+    combinator::{map, verify},
+    IResult,
+};
 
 use crate::config::ParseConfig;
 use crate::elements::{
@@ -635,23 +640,143 @@ pub fn blank_lines_count(input: &str) -> (&str, usize) {
     crate::parse::combinators::blank_lines_count(input).unwrap_or((input, 0))
 }
 
-pub fn parse_headline(input: &str) -> Option<(&str, (&str, usize))> {
-    let (input_, level) = parse_headline_level(input)?;
-    let (input_, content) = lines_while(move |line| {
-        parse_headline_level(line)
-            .map(|(_, l)| l > level)
-            .unwrap_or(true)
-    })(input_)
-    .unwrap_or((input_, ""));
-    Some((input_, (&input[0..level + content.len()], level)))
+// Matches a headline of level <= max_level. This will always be exactly one
+// line, including the terminal \n if one is present. Unlike org-mode (but like
+// org-element), we accept '\n' and EOF to terminate the stars. Returns the
+// number of stars. Must only be called at the start of a line.
+pub(crate) fn parse_headline_level_le(input: &str, max_level: usize) -> IResult<&str, usize, ()> {
+    let (input, level) = verify(
+        map(is_a("*"), |s: &str| s.chars().count()),
+        |level: &usize| *level <= max_level,
+    )(input)?;
+    if !input.is_empty() {
+        one_of("\n ")(input)?;
+        let (input, _) = line_length(input)?;
+        Ok((input, level))
+    } else {
+        Ok((input, level))
+    }
 }
 
-pub fn parse_headline_level(input: &str) -> Option<(&str, usize)> {
-    let (input, stars) = take_while1::<_, _, ()>(|c: char| c == '*')(input).ok()?;
+// Recognizes until end-of-line or end-of-input and returns the length of the
+// line, including the terminal \n (or \r\n) if present.
+fn line_length(input: &str) -> IResult<&str, usize, ()> {
+    match memchr(b'\n', input.as_bytes()) {
+        Some(index) => Ok((&input[index + 1..], index + 1)),
+        None => Ok(("", input.len())),
+    }
+}
+
+// Returns all text until a headline with level <= max_level is found. Must
+// start at the start of the line. Can return nothing if immediately at a
+// headline.
+//
+// This is a separate function from lines_while/lines_until because we need to
+// treat EOF differently from EOL when the file ends with \r.
+pub fn lines_until_headline_at_level_le(
+    input: &str,
+    max_level: usize,
+) -> IResult<&str, (&str, usize), ()> {
+    // Collect lines until EOF or a headline.
+    let mut last = 0;
+    for i in memchr_iter(b'\n', input.as_bytes()) {
+        // Check the first byte after the newline to skip parsing unnecessarily.
+        if input.as_bytes()[last] == b'*'
+            && parse_headline_level_le(&input[last..], max_level).is_ok()
+        {
+            break;
+        }
 
-    if input.starts_with(' ') || input.starts_with('\n') || input.is_empty() {
-        Some((input, stars.len()))
+        last = i + 1;
+    }
+
+    if last < input.len() && parse_headline_level_le(&input[last..], max_level).is_err() {
+        Ok(("", (input, max_level)))
     } else {
-        None
+        Ok((&input[last..], (&input[..last], max_level)))
+    }
+}
+
+pub fn parse_headline(input: &str) -> Option<(&str, (&str, usize))> {
+    // Consume the headline.
+    let (text, level) = parse_headline_level_le(input, std::usize::MAX).ok()?;
+    let (text, _content) = lines_until_headline_at_level_le(text, level).ok()?;
+    let split = input.len() - text.len();
+    Some((&input[split..], (&input[..split], level)))
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_parse_headline() {
+        assert_eq!(parse_headline(""), None);
+        assert_eq!(parse_headline("\n"), None);
+        assert_eq!(parse_headline("Hello"), None);
+        assert_eq!(parse_headline("Hello\n"), None);
+        assert_eq!(parse_headline("Hello\r"), None);
+        assert_eq!(parse_headline("Hello\n\r"), None);
+        assert_eq!(parse_headline("Hello\r\n"), None);
+        assert_eq!(parse_headline("Hello\n*"), None);
+        assert_eq!(parse_headline("Hello\n\n*"), None);
+        assert_eq!(parse_headline("Hello\r\n*"), None);
+        assert_eq!(parse_headline("Hello\n\r\n*"), None);
+        assert_eq!(parse_headline("Hello\r\n\n*"), None);
+        assert_eq!(parse_headline("*"), Some(("", ("*", 1))));
+        assert_eq!(parse_headline("*\n"), Some(("", ("*\n", 1))));
+        assert_eq!(parse_headline("*\n\r"), Some(("", ("*\n\r", 1))));
+        assert_eq!(parse_headline("* "), Some(("", ("* ", 1))));
+        assert_eq!(parse_headline("* \r"), Some(("", ("* \r", 1))));
+        assert_eq!(parse_headline("*\t"), None);
+        assert_eq!(parse_headline("*\t\n"), None);
+        assert_eq!(parse_headline("*\r\n"), None);
+        assert_eq!(parse_headline("* \n"), Some(("", ("* \n", 1))));
+        assert_eq!(parse_headline("* \n\r*"), Some(("", ("* \n\r*", 1))));
+        assert_eq!(parse_headline("* \n\r**"), Some(("", ("* \n\r**", 1))));
+        assert_eq!(parse_headline("*\n*"), Some(("*", ("*\n", 1))));
+        assert_eq!(parse_headline("*\n\n*"), Some(("*", ("*\n\n", 1))));
+        assert_eq!(parse_headline("*\r"), None);
+        assert_eq!(parse_headline("* *"), Some(("", ("* *", 1))));
+        assert_eq!(parse_headline("***\r** Hello\n"), None);
+        assert_eq!(
+            parse_headline("*** ** Hello\n"),
+            Some(("", ("*** ** Hello\n", 3)))
+        );
+        assert_eq!(parse_headline("* Hello"), Some(("", ("* Hello", 1))));
+        assert_eq!(
+            parse_headline("*** Hi\nWorld"),
+            Some(("", ("*** Hi\nWorld", 3)))
+        );
+
+        assert_eq!(
+            parse_headline("* Hello\nText\n** Test\n ** More text\n* World\n"),
+            Some(("* World\n", ("* Hello\nText\n** Test\n ** More text\n", 1)))
+        );
+
+        // We can parse a headline that contains the *\r\n. It is treated as
+        // text in the section.
+        assert_eq!(
+            parse_headline("* \n*\r\n* \n"),
+            Some(("* \n", ("* \n*\r\n", 1)))
+        );
+
+        // We can't parse a headline starting at *\r\n, thus ensuring that each
+        // line either is or is not a headline.
+        assert_eq!(parse_headline("*\r\n* \n"), None);
+
+        assert_eq!(parse_headline("* \n"), Some(("", ("* \n", 1))));
+
+        assert_eq!(
+            parse_headline("* \n**\r\n* \n"),
+            Some(("* \n", ("* \n**\r\n", 1)))
+        );
+
+        assert_eq!(parse_headline("* a\n*"), Some(("*", ("* a\n", 1))));
+        assert_eq!(parse_headline("* a\r\n*"), Some(("*", ("* a\r\n", 1))));
+        assert_eq!(parse_headline("* a\r\n* b"), Some(("* b", ("* a\r\n", 1))));
+        assert_eq!(parse_headline("* a\n* "), Some(("* ", ("* a\n", 1))));
+        assert_eq!(parse_headline("* a\n* \n"), Some(("* \n", ("* a\n", 1))));
+        assert_eq!(parse_headline("* a\n* \n"), Some(("* \n", ("* a\n", 1))));
     }
 }

tests/issue_24.rs

@@ -0,0 +1,18 @@
+use orgize::Org;
+
+#[test]
+fn headline_in_drawer() {
+    // https://github.com/PoiScript/orgize/issues/24
+    // A drawer may not contain a headline.
+    const STARS: &str = "****";
+    for h1 in 1..STARS.len() {
+        for h2 in 1..STARS.len() {
+            let org = crate::Org::parse_string(format!(
+                "{} Hello\n:PROPERTIES:\n{} World\n:END:",
+                &STARS[..h1],
+                &STARS[..h2]
+            ));
+            assert_eq!(org.headlines().count(), 2);
+        }
+    }
+}