A REPL paste's Enter waits on the clock, not on stale core time

sendToRepl timed the Enter's fallback from stepped_ns, which in an idle
detached session is as old as the last frame: the wait was over before it
began and the \r went out with the paste, which 3.13's REPL then reads as
part of it (4 of 5 sends lost their Enter). The wait now starts from the
host's clock and is checked against now_ns; the REPL's echo of the paste
still sends it sooner, and the wake is scheduled for the deadline. fs.py
sends five times after two idle seconds each in a real pty.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/exec.zig b/src/exec.zig
index 484b85d7..963c8763 100644
--- a/src/exec.zig
+++ b/src/exec.zig
@@ -450,7 +450,7 @@ const repl_enter_wait_ns: u64 = 250 * std.time.ns_per_ms;
 pub fn flushReplEnter(p: *Pardes, id: usize, answered: bool) void {
     const pane = p.panes[id] orelse return;
     if (pane.repl_enter == 0) return;
-    if (!answered and p.stepped_ns < pane.repl_enter_due_ns) return;
+    if (!answered and p.now_ns < pane.repl_enter_due_ns) return;
     for (0..pane.repl_enter) |_| p.emitWrite(id, "\r");
     pane.repl_enter = 0;
 }
@@ -499,7 +499,12 @@ pub fn sendToRepl(p: *Pardes, from: usize, to: usize, text: []const u8) void {
         // It goes once the REPL has answered the paste (its next output),
         // or after a moment if nothing comes.
         dst.repl_enter = enters;
-        dst.repl_enter_due_ns = p.stepped_ns + repl_enter_wait_ns;
+        // From the clock now, not core time: idle (a detached session
+        // nobody watches), `stepped_ns` and `now_ns` are as old as the last
+        // frame, and a wait counted from there would be over already, the
+        // Enter going out with the paste.
+        const now = if (p.host.vtable.now) |clock| clock(p.host.ctx) else p.now_ns;
+        dst.repl_enter_due_ns = now + repl_enter_wait_ns;
     } else for (0..enters) |_| p.emitWrite(to, "\r");
     // Line by line, a blank line inside a Python block ends the block.
     if (!panes.Terminal.bracketedPaste(dst) and !dst.repl_warned and (if (dst.repl) |r| r.lang == python_lang else false) and