A terminal's Tty word names its shell, Tty+fish, and a click on it opens another

A terminal's tag said Tty whatever shell it ran. The host's acknowledgement
of the shell it forked now sets the word to Tty+<shell>, tinted like the tag's
name. Word+arg is taken as Word arg, one word a tag can hold and a click can
take whole (+ is a word character), so Tty+fish opens a terminal on fish, as
Tty fish does; Tty takes the shell as its argument, which the host forks for
that pane instead of the configured one. Every snapshot whose screen shows a
terminal's tag changes: 69 goldens, re-recorded by name, whose 297 changed
lines are all Tty becoming Tty+bash (the harness runs bash), the cursor
columns and style spans that moved with it, or that text cut at a pane's
width.

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

1 files changed, 24 insertions, 1 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index 1bb13e3d..e92fb3f7 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -631,8 +631,9 @@ test "pane-tag Exec prefers Tty and argument builtins before shell fallback" {
     while (p.nextEffect()) |_| {} // initial shell spawn/geometry
     p.acknowledgeShell(0, "/bin/sh", false);
 
+    // The Tty word names the shell the host ran, and opens another of it.
     const pane = p.panes[0].?;
-    try std.testing.expectEqualStrings(tagline.terminal_pane_tail, tagline.curTail(pane));
+    try std.testing.expectEqualStrings(" Tty+sh" ++ tagline.terminal_pane_tail[" Tty".len..], tagline.curTail(pane));
     const tag_x = p.rects[0].x + TAG_TEXT_INSET;
     const tag_y = p.rects[0].y;
 
@@ -654,6 +655,7 @@ test "pane-tag Exec prefers Tty and argument builtins before shell fallback" {
     };
     try std.testing.expectEqual(panes_before + 1, panes_after);
     try std.testing.expect(p.panes[p.active].?.isTerminal());
+    try std.testing.expectEqualStrings("sh", p.panes[p.active].?.shell.?);
 
     // Argument-taking builtins use the same gesture path: a tag sweep is the
     // complete command line, and Theme consumes its tail without a PTY write.
@@ -1359,6 +1361,17 @@ test "Exec in a terminal whose tty is taken runs as a command pane instead of ty
     try std.testing.expect(spawned);
 }
 
+test "Tty+fish, one word a tag can hold, opens a terminal on that shell" {
+    const p = try Pardes.init(std.testing.allocator, .{ .tty_only = true });
+    defer p.deinit();
+    while (p.nextEffect()) |_| {}
+    try std.testing.expect(p.executeBuiltinLine(0, "Tty+fish"));
+    try std.testing.expect(p.active != 0);
+    try std.testing.expectEqualStrings("fish", p.panes[p.active].?.shell.?);
+    p.acknowledgeShell(p.active, "/usr/bin/fish", true);
+    try std.testing.expect(std.mem.startsWith(u8, tagline.curTail(p.panes[p.active].?), " Tty+fish "));
+}
+
 test "a command pane shows how its command ended, and the next command there runs below it" {
     const gpa = std.testing.allocator;
     const p = try Pardes.init(gpa, .{});
@@ -4188,6 +4201,7 @@ pub const Pardes = struct {
         for (0..pane.pointer_selections.len) |slot| pane.clearPointerSelection(slot);
         panes.Terminal.deinitPendingCommand(pane);
         if (pane.command) |line| p.gpa.free(line);
+        if (pane.shell) |bin| p.gpa.free(bin);
         if (pane.image) |*iv| {
             iv.deinit(p.image_gpa);
         }
@@ -4371,6 +4385,15 @@ pub const Pardes = struct {
         if (id < MAX_PANES) if (p.panes[id]) |pane| {
             ctlfs.pty.shellGone(p, pane, true); // a respawn replaced whatever ran
             pane.fs.unmarked = !prompt_marks;
+            // The tag's Tty word names the shell the host ran, and a click
+            // on it (`Tty+fish`) opens another of the same.
+            if (pane.command == null) {
+                const base = std.fs.path.basename(executable);
+                const rest = tagline.terminal_pane_tail[" Tty".len..];
+                if (std.fmt.bufPrint(&pane.shell_tail, " Tty+{s}{s}", .{ base, rest })) |tail| {
+                    pane.shell_tail_len = @intCast(tail.len);
+                } else |_| {}
+            }
         };
         if (id < MAX_PANES) panes.Terminal.shellSpawned(p, id, prompt_marks);
         if (p.settings.shell.effective.set(executable))