Documents: a drawn CRLF reads back to its start

A press at a CRLF line's end typed between CR and LF.

Co-Authored-By: Claude Opus 5.5 (1M context) <noreply@anthropic.com>

src/documents/document/tests/point.rs

@@ -89,6 +89,17 @@ fn a_press_opens_the_block_at_the_pressed_character(cx: &mut TestAppContext) {
     );
 }
 
+#[gpui::test]
+fn a_press_past_a_crlf_line_types_before_its_end(cx: &mut TestAppContext) {
+    let source = "one\r\ntwo\r\n";
+    let (document, cx) = open(source, MarkdownMode::Visual, cx);
+    press_on(0, 3, MouseButton::Left, cx);
+    assert_eq!(opened_caret(&document, cx), "one".len());
+    cx.simulate_input("X");
+    cx.simulate_keystrokes("escape");
+    assert_eq!(super::text(&document, cx), "oneX\r\ntwo\r\n");
+}
+
 #[gpui::test]
 fn a_secondary_press_moves_the_caret_and_opens_nothing(cx: &mut TestAppContext) {
     let (document, cx) = open(TEXT, MarkdownMode::Visual, cx);

src/documents/tree/mod.rs

@@ -180,7 +180,7 @@ pub fn parse(markdown: &str) -> Vec<Node> {
 }
 
 impl<'a> Reader<'a> {
-    /// A reader of `root`, parsed from `source`, as the screen draws it.
+    /// Reads `root`, parsed from `source`, as drawn on screen.
     pub fn new(source: &'a str, root: &mdast::Node) -> Self {
         Self::reading(source, root, true)
     }

src/documents/tree/sources.rs

@@ -319,12 +319,8 @@ fn aligned(drawn: &str, written: &str, escapes: Escapes) -> Vec<(usize, usize)>
             let Some(s) = source[..j].last() else {
                 return out;
             };
-            if d == s.ch {
+            // A line's end, drawn or joined; CRLF is one end.
-                j -= 1;
+            if d == s.ch || (d.is_whitespace() && s.ends_line()) {
-                break s.at;
-            }
-            // A join: a line's end drawn as white space.
-            if d.is_whitespace() && s.ends_line() {
                 j -= 1;
                 if s.ch == '\n' && j > 0 && source[j - 1].ch == '\r' && source[j - 1].raw == s.raw {
                     j -= 1;
@@ -393,6 +389,15 @@ mod tests {
         assert_eq!(under(source, "next"), source.find("next").unwrap());
     }
 
+    #[test]
+    fn a_drawn_crlf_reads_back_to_its_start() {
+        let source = "one\r\ntwo";
+        let inline = first(source);
+        let end = inline.text.find('\n').expect("a drawn line end");
+        assert_eq!(inline.source_at(source, end), Some(3));
+        assert_eq!(under(source, "two"), source.find("two").unwrap());
+    }
+
     #[test]
     fn joins_escapes_and_indents_read_back() {
         let source = "a \\*star\\* x\n   y";