Fix block scalars and document end interaction.

parser/src/scanner.rs

@@ -612,6 +612,16 @@ impl<T: Iterator<Item = char>> Scanner<T> {
         }
     }
 
+    /// Check whether the next characters correspond to an end of document.
+    ///
+    /// [`Self::lookahead`] must have been called before calling this function.
+    fn next_is_document_end(&self) -> bool {
+        self.buffer[0] == '.'
+            && self.buffer[1] == '.'
+            && self.buffer[2] == '.'
+            && is_blankz(self.buffer[3])
+    }
+
     /// Insert a token at the given position.
     fn insert_token(&mut self, pos: usize, tok: Token) {
         let old_len = self.tokens.len();
@@ -1592,6 +1602,12 @@ impl<T: Iterator<Item = char>> Scanner<T> {
         let start_mark = self.mark;
 
         while self.mark.col == indent && !is_z(self.ch()) {
+            if indent == 0 {
+                self.lookahead(4);
+                if self.next_is_document_end() {
+                    break;
+                }
+            }
             // We are at the beginning of a non-empty line.
             trailing_blank = is_blank(self.ch());
             if !literal && !leading_break.is_empty() && !leading_blank && !trailing_blank {

parser/tests/yaml-test-suite.rs

@@ -220,7 +220,7 @@ fn events_differ(actual: Vec<String>, expected: &str) -> Option<String> {
                     continue;
                 } else {
                     Some(format!(
-                        "line {} differs: expected `{}`, found `{}`",
+                        "line {} differs: \n=> expected `{}`\n=>    found `{}`",
                         idx, exp, act
                     ))
                 }
@@ -297,8 +297,6 @@ fn expected_events(expected_tree: &str) -> Vec<String> {
 
 #[rustfmt::skip]
 static EXPECTED_FAILURES: &[&str] = &[
-    // Directives (various)
-    "W4TN", // scalar confused as directive
     // Losing trailing newline
     "JEF9-02",
     "L24T-01",