+Errors with no room anywhere logs its text rather than fail the Edit

Edit's p and = put their output in +Errors, and when its column had no
room the placement refusal failed the whole Edit. +Errors now tries every
column with room, the last first, and with none its text is logged as msg
records, a line each; the Edit succeeds.

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

2 files changed, 19 insertions, 0 deletions

diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index 25abd9b5..378dd844 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -1447,3 +1447,16 @@ test "an exec line over the command limit fails the write and says the limit; a
     try testing.expect(th.logHas(p, "a command line is at most 1024 bytes"));
     try testing.expectEqual(Status.ok, wr(p, root_exec, "Msg " ++ "z" ** 1100 ++ "\n").reply.status);
 }
+
+test "Edit's p and = never fail for want of room for +Errors: the text is logged instead" {
+    const p = try withFile(testing.allocator, "one\ntwo\n");
+    defer p.deinit();
+    p.update(.{ .resize = .{ .cols = 80, .rows = 6 } });
+    const ctl_node = Node.of(serialOf(p), .ctl);
+    try testing.expectEqual(Status.ok, wr(p, ctl_node, "Edit ,p\n").reply.status);
+    try testing.expect(th.logHas(p, " one\n") and th.logHas(p, " two\n"));
+    p.sync();
+    var count: usize = 0;
+    for (p.panes) |slot| count += @intFromBool(slot != null);
+    try testing.expectEqual(@as(usize, 1), count); // the +Errors that had no room is gone
+}
diff --git a/src/ninep/pane.zig b/src/ninep/pane.zig
index 3307eb47..791cb797 100644
--- a/src/ninep/pane.zig
+++ b/src/ninep/pane.zig
@@ -649,6 +649,12 @@ pub fn appendErrors(p: *Pardes, id: usize, text: []const u8) ?usize {
         return null;
     };
     exec.placeNew(p, id, id, free, .errors);
+    // No column had room for it (it closes at the step's end): the text is
+    // logged instead, a msg a line, so it is not lost and nothing fails.
+    if (p.unplaced.isSet(free)) {
+        var lines = std.mem.splitScalar(u8, std.mem.trimEnd(u8, text, "\n"), '\n');
+        while (lines.next()) |line| events.noteMessage(p, pane.serial, line[0..@min(line.len, pardes.Messages.LoggedMessage.cap)]);
+    }
     return text.len;
 }