Merge pull request #2658 from ghostty-org/push-sstnrxoppstv

termio: handle empty titles (OSC 0/2)

src/terminal/osc.zig

@@ -400,7 +400,7 @@ pub const Parser = struct {
             .@"0" => switch (c) {
                 ';' => {
                     self.command = .{ .change_window_title = undefined };
-
+                    self.complete = true;
                     self.state = .string;
                     self.temp_state = .{ .str = &self.command.change_window_title };
                     self.buf_start = self.buf_idx;
@@ -477,7 +477,7 @@ pub const Parser = struct {
                 '2' => self.state = .@"22",
                 ';' => {
                     self.command = .{ .change_window_title = undefined };
-
+                    self.complete = true;
                     self.state = .string;
                     self.temp_state = .{ .str = &self.command.change_window_title };
                     self.buf_start = self.buf_idx;
@@ -1159,6 +1159,17 @@ test "OSC: change_window_title with utf8" {
     try testing.expectEqualStrings("— ‐", cmd.change_window_title);
 }
 
+test "OSC: change_window_title empty" {
+    const testing = std.testing;
+
+    var p: Parser = .{};
+    p.next('2');
+    p.next(';');
+    const cmd = p.end(null).?;
+    try testing.expect(cmd == .change_window_title);
+    try testing.expectEqualStrings("", cmd.change_window_title);
+}
+
 test "OSC: change_window_icon" {
     const testing = std.testing;
 

src/termio/stream_handler.zig

@@ -965,7 +965,23 @@ pub const StreamHandler = struct {
         @memcpy(buf[0..title.len], title);
         buf[title.len] = 0;
 
-        // Mark that we've seen a title
+        // Special handling for the empty title. We treat the empty title
+        // as resetting to as if we never saw a title. Other terminals
+        // behave this way too (e.g. iTerm2).
+        if (title.len == 0) {
+            // If we have a pwd then we set the title as the pwd else
+            // we just set it to blank.
+            if (self.terminal.getPwd()) |pwd| pwd: {
+                if (pwd.len >= buf.len) break :pwd;
+                @memcpy(buf[0..pwd.len], pwd);
+                buf[pwd.len] = 0;
+            }
+
+            self.surfaceMessageWriter(.{ .set_title = buf });
+            self.seen_title = false;
+            return;
+        }
+
         self.seen_title = true;
         self.surfaceMessageWriter(.{ .set_title = buf });
     }