Merge PR #2859: Treat CRLF as a single line break in fonts::wrap

crates/fonts/src/lib.rs

@@ -69,7 +69,7 @@ fn is_wide(c: char) -> bool {
     )
 }
 
-/// Greedy line breaking within `width` points (paragraphs split on newlines; words longer
+/// Greedy line breaking within `width` points (paragraphs split on line breaks, where CRLF counts as one; words longer
 /// than a line are broken by character).
 pub fn wrap(text: &str, size: f64, width: f64) -> Vec<String> {
     wrap_with(text, size, width, helvetica_width)
@@ -78,7 +78,8 @@ pub fn wrap(text: &str, size: f64, width: f64) -> Vec<String> {
 /// [`wrap`], measuring with `measure` (for example [`cjk_width`]).
 pub fn wrap_with(text: &str, size: f64, width: f64, measure: impl Fn(&str, f64) -> f64) -> Vec<String> {
     let mut lines = Vec::new();
-    for para in text.split(['\n', '\r']) {
+    // A CRLF pair is one break, a lone CR or LF is one break each.
+    for para in text.replace("\r\n", "\n").split(['\n', '\r']) {
         let mut line = String::new();
         // No word is on the line yet; an empty word (a leading space) still starts it.
         let mut fresh = true;
@@ -277,6 +278,15 @@ mod tests {
         assert_eq!(broken, wrap(" abcdefghijklmnopqrstuvwxyz", 11.0, 40.0));
     }
 
+    #[test]
+    fn crlf_is_one_line_break() {
+        assert_eq!(wrap("a\r\nb", 12.0, 100.0), ["a", "b"]);
+        assert_eq!(wrap("a\rb", 12.0, 100.0), ["a", "b"]);
+        assert_eq!(wrap("a\nb", 12.0, 100.0), ["a", "b"]);
+        assert_eq!(wrap("a\r\n\r\nb", 12.0, 100.0), ["a", "", "b"]);
+        assert_eq!(wrap("a\n\rb", 12.0, 100.0), ["a", "", "b"]);
+    }
+
     #[test]
     fn win_ansi_encodability_matches_the_encoder() {
         for c in ['a', 'é', 'ÿ', '€', '—', '™', '\t', '?'] {