Insert on a terminal's text says it edits a copy, run with Tab or B2, that the program's next drawing replaces, and that Ctrl-b types to the program

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

3 files changed, 19 insertions, 0 deletions

diff --git a/src/edit.zig b/src/edit.zig
index bf65935e..b2909d87 100644
--- a/src/edit.zig
+++ b/src/edit.zig
@@ -2166,6 +2166,18 @@ test "Enter in insert mode keeps a tab-indented line's tabs, as o and O do" {
     try std.testing.expect(std.mem.startsWith(u8, pane.file.?.content, "\t\tvalue = 1;\n\t\t\n"));
 }
 
+test "insert on a terminal's text says it edits a copy the program's next drawing replaces" {
+    const p = try Pardes.init(std.testing.allocator, .{ .tty_only = true });
+    defer p.deinit();
+    while (p.nextEffect()) |_| {}
+    const pane = p.panes[0].?;
+    if (!pane.isTerminal()) return error.SkipZigTest;
+    pane.body.mode = .normal;
+    p.update(.{ .key = .{ .cp = 'i' } });
+    p.update(.{ .key = .{ .cp = 'x', .text = "x" } });
+    try std.testing.expect(std.mem.indexOf(u8, pane.msg[0..pane.msg_len], "a copy of the terminal's text") != null);
+}
+
 test "insert and normal modes edit complete Unicode graphemes" {
     const gpa = std.testing.allocator;
     const p = try Pardes.init(gpa, .{ .cols = 60, .rows = 12 });
diff --git a/src/terminal.zig b/src/terminal.zig
index 140dae76..3bb1fbda 100644
--- a/src/terminal.zig
+++ b/src/terminal.zig
@@ -1637,6 +1637,11 @@ pub fn editText(p: *Pardes, pane: *Pane, lo: i32, hi: i32, col: i32) ?EditText {
         if (pane.ovl) |overlay| p.gpa.free(overlay.text);
         pane.ovl = .{ .row = row0, .rows = covered, .text = text };
     }
+    // A terminal's text is its program's: edited here it is a copy, to run
+    // with Tab or B2, gone when the program draws again. Said at its first
+    // edit, so it never looks like an edit that was lost.
+    if (fresh) for (p.panes, 0..) |slot, id| if (slot == pane)
+        p.setMessage(id, "a copy of the terminal's text: Tab or B2 runs it; what the program draws next replaces it (Ctrl-b types to the program)");
     return .{ .text = pane.ovl.?.text, .row0 = pane.ovl.?.row };
 }
 
diff --git a/test/snapshots/ttyedit.golden b/test/snapshots/ttyedit.golden
index ab1b1b5b..70ab8504 100644
--- a/test/snapshots/ttyedit.golden
+++ b/test/snapshots/ttyedit.golden
@@ -22,12 +22,14 @@
 |  words.txt
 == snap split grid=100x31 cursor=2,9
 |2: ^  /tmp/pardes-snap/ttyedit/cwd Tty+bash Save Mode   /tmp/pardes-snap/ttyedit/cwd Tty+bash Save Mode
+|4:    next replaces it (Ctrl-b types to the program)   ls
 |8:   one t
 |9:   wo three
 |10:   four five six
 |11:   seven eight nine
 == snap opened grid=100x31 cursor=6,10
 |2:    /tmp/pardes-snap/ttyedit/cwd Tty+bash Save Mode   /tmp/pardes-snap/ttyedit/cwd Tty+bash Save Mode
+|4:   ls                                                ls
 |10:   OPEN
 |11:   four five six
 |12:   seven eight nine