Columns are named by stable serials over 9P, as panes are

/col/<n> named a column by its index, which shifts when a column left of it
closes: exactly what scripts trip on. A column is now /col/<serial>, its
serial kept while it lives and never reused; /layout lines give serial and
index (`<serial> <index> ...`), active names the serial, /index's last
field is the column's serial, and the log says newcol and delcol with
serials. Docs, the skill and the tree's README say so.

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

1 files changed, 8 insertions, 7 deletions

diff --git a/src/ninep/pane.zig b/src/ninep/pane.zig
index 6542d747..c594c7a3 100644
--- a/src/ninep/pane.zig
+++ b/src/ninep/pane.zig
@@ -265,10 +265,11 @@ pub fn fileSize(p: *Pardes, id: usize, f: PaneFile) u64 {
 
 // ---- the index ----
 
-/// The column a pane is in, as /layout and /col number them; the last word
-/// of its /index line.
-pub fn columnOf(p: *const Pardes, id: usize) usize {
-    return if (pardes.layout.findPane(p, id)) |at| at.col else 0;
+/// The serial of the column a pane is in, as /layout and /col name it; the
+/// last word of its /index line.
+pub fn columnOf(p: *Pardes, id: usize) u32 {
+    const at = pardes.layout.findPane(p, id) orelse return 0;
+    return pardes.layout.columnSerial(p, at.col);
 }
 
 pub fn indexLen(p: *Pardes) u64 {
@@ -710,7 +711,7 @@ test "index lists serial kind dirty flag and name and stat reports its length" {
     const a = rd(p, index, 0, 4096);
     try testing.expectEqual(Status.ok, a.reply.status);
     var want: [64]u8 = undefined;
-    const clean_row = try std.fmt.bufPrint(&want, "{d} text 0 /test.txt 0\n", .{pane.serial});
+    const clean_row = try std.fmt.bufPrint(&want, "{d} text 0 /test.txt {d}\n", .{ pane.serial, columnOf(p, 0) });
     try testing.expect(std.mem.indexOf(u8, a.bytes, clean_row) != null);
     const at = std.mem.indexOf(u8, a.bytes, clean_row).?;
     const stat = call(p, .{ .tag = 1, .op = .getattr, .node = index });
@@ -719,7 +720,7 @@ test "index lists serial kind dirty flag and name and stat reports its length" {
 
     pane.file.?.saved_revision = pane.file.?.revision -% 1;
     var dirty_want: [64]u8 = undefined;
-    const dirty_row = try std.fmt.bufPrint(&dirty_want, "{d} text 1 /test.txt 0\n", .{pane.serial});
+    const dirty_row = try std.fmt.bufPrint(&dirty_want, "{d} text 1 /test.txt {d}\n", .{ pane.serial, columnOf(p, 0) });
     try testing.expect(std.mem.indexOf(u8, rd(p, index, 0, 4096).bytes, dirty_row) != null);
     const kind = at + std.mem.indexOfScalar(u8, clean_row, ' ').? + 1;
     try testing.expectEqualStrings("text", rd(p, index, kind, 4).bytes);
@@ -741,7 +742,7 @@ test "a terminal is listed as term with its directory as name" {
     try testing.expect(std.mem.indexOf(
         u8,
         rd(p, @intFromEnum(tree.TopFile.index), 0, 4096).bytes,
-        try std.fmt.bufPrint(&want, "{d} term 0 /work/dir 0\n", .{pane.serial}),
+        try std.fmt.bufPrint(&want, "{d} term 0 /work/dir {d}\n", .{ pane.serial, columnOf(p, 0) }),
     ) != null);
     try testing.expectEqualStrings("/work/dir\n", rd(p, Node.of(pane.serial, .name), 0, 4096).bytes);
     const refused = wr(p, Node.of(pane.serial, .name), "/elsewhere\n");