T40: review round 2: the session's title comes from the tap alone, in the output's order, so the row, the window and a notification name it alike: OSC 0 and 2 read as vte splits them, 15 parts past the number, and up to 65536 bytes; alacritty's title events, which come later, pass by, and a full reset no longer sets the options again to send one

src/term/pty/tests.rs

@@ -181,15 +181,20 @@ fn osc_99_gathers_a_full_encoded_chunk_and_the_lines_base64_carries() {
 
 #[test]
 fn titles_reach_the_session_in_their_place_among_notifications() {
+    let long = "y".repeat(5000);
+    let many: Vec<String> = (1..=17).map(|at| at.to_string()).collect();
     let parts = [
-        "\\033]2;Old\\007",
-        "\\033[22t",
-        "\\033]2;New\\007",
-        "\\033]9;a\\007",
-        "\\033[23t",
-        "\\033]9;b\\007",
-        "\\033c",
-        "\\033]9;c\\007",
+        "\\033]2;Old\\007".to_string(),
+        "\\033[22t".into(),
+        "\\033]2;New\\007".into(),
+        "\\033]9;a\\007".into(),
+        "\\033[23t".into(),
+        "\\033]9;b\\007".into(),
+        "\\033c".into(),
+        "\\033]9;c\\007".into(),
+        format!("\\033]2;{long}\\007"),
+        format!("\\033]2;{}\\007", many.join(";")),
+        "\\033]9;d\\007".into(),
     ];
     let whole = run(&format!("printf '{}x'", parts.concat()), (40, 4));
     let split: Vec<String> = parts
@@ -198,13 +203,16 @@ fn titles_reach_the_session_in_their_place_among_notifications() {
         .collect();
     let split = run(&format!("{}; printf x", split.join("; ")), (40, 4));
     let said = [
-        "title Old",
-        "title New",
-        "show a",
-        "title Old",
-        "show b",
-        "reset",
-        "show c",
+        "title Old".to_string(),
+        "title New".into(),
+        "show a".into(),
+        "title Old".into(),
+        "show b".into(),
+        "reset".into(),
+        "show c".into(),
+        format!("title {long}"),
+        format!("title {}", many[..15].join(";")),
+        "show d".into(),
     ];
     assert_eq!(whole.said, said, "one write");
     assert_eq!(split.said, said, "a write a sequence");

src/term/shell/tests.rs

@@ -108,7 +108,7 @@ impl Run {
             );
             match self.events.try_recv() {
                 Ok(PtyEvent::Folder(folder)) => self.folders.push(folder),
-                Ok(PtyEvent::Term(Event::Title(title))) => self.titles.push(title),
+                Ok(PtyEvent::Title(title)) => self.titles.push(title),
                 Ok(PtyEvent::Mark(mark)) => self.marks.push(mark),
                 Ok(PtyEvent::Term(Event::PtyWrite(reply))) => self.pty.write(reply.into_bytes()),
                 Ok(PtyEvent::Term(Event::ChildExit(status))) => {

src/term/tap.rs

@@ -14,7 +14,7 @@ use super::{
     prompts::{self, Prompts},
     pty::PtyEvent,
     status,
-    titles::Titles,
+    titles::{self, Titles},
 };
 
 /// The longest OSC body kept; longer ones are dropped whole.
@@ -314,10 +314,12 @@ impl Osc {
         }
     }
 
-    /// The longest body kept: an OSC 99 holds a payload of 4096 bytes past its metadata.
+    /// The longest body kept: an OSC 99's holds its payload past its metadata, a title's more.
     fn most(&self) -> usize {
         if self.body.starts_with(b"99;") {
             notify::BODY
+        } else if self.body.starts_with(b"0;") || self.body.starts_with(b"2;") {
+            titles::LONGEST
         } else {
             MOST
         }

src/term/tap/tests.rs

@@ -259,3 +259,22 @@ fn finds_the_title_stack_s_push_and_pop_as_vte_reads_them() {
         ["PUSH", "2;t", "POP"]
     );
 }
+
+#[test]
+fn a_title_s_body_holds_65536_bytes_and_another_s_4096() {
+    let osc = |number: &str, length: usize| {
+        [
+            format!("\x1b]{number};").as_bytes(),
+            &vec![b'a'; length],
+            b"\x07",
+        ]
+        .concat()
+    };
+    let longest = scan(&[&osc("2", titles::LONGEST - 2)]);
+    assert_eq!(longest.concat().len(), titles::LONGEST);
+    assert!(scan(&[&osc("0", titles::LONGEST - 1)]).is_empty());
+    assert!(
+        scan(&[&osc("7", MOST - 1)]).is_empty(),
+        "another stays at 4096"
+    );
+}

src/term/titles.rs

@@ -1,7 +1,13 @@
 /// The titles alacritty saves before it drops the oldest.
 const SAVED: usize = 4096;
 
-/// A program's title as alacritty keeps it, read in the output's order: OSC 0 and 2 set it, CSI 22 t saves it, CSI 23 t brings it back, a full reset empties both.
+/// vte keeps 16 parameters of an OSC, its number among them.
+const PARTS: usize = 15;
+
+/// The longest OSC 0 or 2 body the tap keeps; a longer one drops, logged.
+pub(super) const LONGEST: usize = 65536;
+
+/// The title a session shows, read in the output's order as vte and alacritty read it.
 #[derive(Default)]
 pub(crate) struct Titles {
     /// Empty while the program names none.
@@ -10,10 +16,11 @@ pub(crate) struct Titles {
 }
 
 impl Titles {
-    /// Sets the title an OSC 0 or 2 body past its number names: its UTF-8 parameters joined by `;` and trimmed, as alacritty joins them.
+    /// Sets the title from an OSC 0 or 2 body past its number, as vte splits it and alacritty joins it.
     pub fn set(&mut self, rest: &[u8]) -> String {
         let parts: Vec<&str> = rest
             .split(|&byte| byte == b';')
+            .take(PARTS)
             .filter_map(|part| std::str::from_utf8(part).ok())
             .collect();
         self.title = parts.join(";").trim().to_owned();
@@ -56,6 +63,12 @@ mod tests {
             "a part not in UTF-8 passes by"
         );
         assert_eq!(titles.set(b""), "");
+        let parts: Vec<String> = (1..=17).map(|at| at.to_string()).collect();
+        assert_eq!(
+            titles.set(parts.join(";").as_bytes()),
+            parts[..PARTS].join(";"),
+            "vte keeps 16 parameters, the number among them"
+        );
     }
 
     #[test]

src/term/view.rs

@@ -276,10 +276,14 @@ impl TerminalView {
                     self.ask(ask, cx);
                     self.restate(cx);
                 }
-                PtyEvent::Title(title) => self.title = title,
+                PtyEvent::Title(title) => {
+                    self.title.clone_from(&title);
+                    cx.emit(TerminalEvent::Title(title));
+                }
                 PtyEvent::Reset => {
                     self.records.reset();
                     self.title.clear();
+                    cx.emit(TerminalEvent::Title(String::new()));
                     self.restate(cx);
                 }
             }
@@ -294,20 +298,11 @@ impl TerminalView {
     fn term_event(&mut self, event: Event, cx: &mut Context<Self>) {
         match event {
             Event::Wakeup => self.shown = true,
-            Event::MouseCursorDirty => {}
-            // A reset empties the title and sends only this; setting the options sends the title.
-            Event::CursorBlinkingChange => {
-                let settings = config(SettingsStore::get(cx));
-                self.pty.term.lock().set_options(settings);
-            }
-            Event::Title(title) => {
-                self.title.clone_from(&title);
-                cx.emit(TerminalEvent::Title(title));
-            }
-            Event::ResetTitle => {
-                self.title.clear();
-                cx.emit(TerminalEvent::Title(String::new()));
-            }
+            // The tap reads the title in the output's order; alacritty's title events come after it.
+            Event::MouseCursorDirty
+            | Event::CursorBlinkingChange
+            | Event::Title(_)
+            | Event::ResetTitle => {}
             Event::Bell => {
                 log::debug!("terminal {}: a bell, kept silent", self.pty.pid);
                 cx.emit(TerminalEvent::Bell);