A command of several lines keeps its pane's tag to one row, and the tag never panics on a longer prefix

A two-line exec made a command pane whose tag prefix held the line's newline,
so the tag ran to a second row and tagTintRange sliced its first row past its
end: panic. acme runs a multi-line selection as one command, and so does
pardes; the tag now shows the line's first row, cut at a character's start,
and '...', tagTintRange stays inside the row it is given, and the '% line'
echo turns the line's newlines into the terminal's, so it does not
staircase.

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

1 files changed, 27 insertions, 0 deletions

diff --git a/src/pardes.zig b/src/pardes.zig
index 9821839f..80a20a0d 100644
--- a/src/pardes.zig
+++ b/src/pardes.zig
@@ -1361,6 +1361,33 @@ test "Exec in a terminal whose tty is taken runs as a command pane instead of ty
     try std.testing.expect(spawned);
 }
 
+test "a command of several lines keeps its tag one row, and its echo does not staircase" {
+    const gpa = std.testing.allocator;
+    const p = try Pardes.init(gpa, .{ .tty_only = true, .cols = 100, .rows = 30 });
+    defer p.deinit();
+    while (p.nextEffect()) |_| {}
+    const doc = try p.newDocPane(1);
+    doc.image = .{ .path = try gpa.dupe(u8, "/tmp/pic.ppm") };
+    const two = "def greet(name):\n    return name\n\nprint(greet(\"x\"))\n";
+    const dst = exec.execute(p, 1, two) orelse return error.NoCommandPane;
+    while (p.nextEffect()) |_| {}
+    const pane = p.panes[dst].?;
+    const prefix = try tagline.tagPrefix(p, pane);
+    try std.testing.expect(std.mem.indexOfScalar(u8, prefix, '\n') == null);
+    try std.testing.expect(std.mem.indexOf(u8, prefix, "(def greet(name):...) running") != null);
+    // Rendered without a panic, however the tag wraps.
+    var frame = std.heap.ArenaAllocator.init(gpa);
+    defer frame.deinit();
+    _ = try p.render(frame.allocator());
+    p.update(.{ .exited = .{ .pane = @intCast(dst), .status = 0 } });
+    _ = exec.execute(p, 1, two);
+    while (p.nextEffect()) |_| {}
+    _ = try p.render(frame.allocator());
+    const body = try panes.Terminal.screenTextAlloc(pane, gpa);
+    defer gpa.free(body);
+    try std.testing.expect(std.mem.indexOf(u8, body, "% def greet(name):\n    return name") != null);
+}
+
 test "a spawn is for the pane it was made for, not whatever took the slot since" {
     const gpa = std.testing.allocator;
     const p = try Pardes.init(gpa, .{ .tty_only = true });