A column can be empty, as acme's can; new panes go where acme's makenewwindow puts them

Newcol makes an empty column; closing a column's last pane leaves it empty with
the keyboard on its tag; Delcol and Joincol alone take a column away; the
session's last pane closing quits. The +New stand-in and replaceStillborn /
stillborn_joiner are gone. Every new pane goes through exec.placeNew, which
follows acme's makenewwindow (active column, empty column whole, blank space,
halving the biggest) or, with Placement pardes, the old rules. ColumnTags is
gone: column tags are always shown. A grip drag shows acme's box cursor.

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

1 files changed, 15 insertions, 10 deletions

diff --git a/src/builtins.zig b/src/builtins.zig
index 72df0271..c2b4d62f 100644
--- a/src/builtins.zig
+++ b/src/builtins.zig
@@ -169,7 +169,7 @@ pub const registry = struct {
         inline for (comptime settingList(), manualBuiltinCount()..) |setting, i|
             if (@intFromEnum(b) == i) return switch (setting.action) {
                 // a switch flips bare, and DumpDir bare is the default
-                .toggle, .transition, .scene, .dump_dir => false,
+                .toggle, .transition, .scene, .dump_dir, .placement => false,
                 .shell, .theme, .font, .tagline_size, .window_opacity, .window_blur, .message_ms, .shader, .shader_animation => true,
             };
         unreachable;
@@ -818,11 +818,11 @@ pub const New = struct {
     }
 };
 
-/// The same empty scratch, opened in a fresh column beside the calling pane.
+/// An empty column right of the keyboard's, its tag taking the keyboard.
 pub const Newcol = struct {
     pub const scope: Scope = .session;
     pub fn run(c: Ctx) void {
-        c.p.newScratchColumn(c.id);
+        c.p.newColumn(c.id);
     }
 };
 
@@ -937,7 +937,10 @@ pub const Collapse = struct {
 
 pub const Delcol = struct {
     pub fn run(c: Ctx) void {
-        c.p.removeColumn(c.id) catch |err| c.p.reportError(c.id, "close column", err);
+        // The column of the tag it came from, else the pane's: a pane ctl's
+        // Delcol closes that pane's column wherever the keyboard is.
+        const col = c.p.exec_column orelse (layout.findPane(c.p, c.id) orelse return).col;
+        c.p.removeColumn(col) catch |err| c.p.reportError(c.id, "close column", err);
     }
 };
 
@@ -1049,9 +1052,9 @@ pub const Joincol = struct {
     pub const scope: Scope = .session;
     pub fn run(c: Ctx) void {
         // The keyboard's column joins the one to its right; the last has none.
-        const at = layout.findPane(c.p, c.p.active) orelse return;
-        if (at.col + 1 >= c.p.ncol) return c.p.reportFailure(c.id, "Joincol: no column to the right");
-        layout.joinCol(c.p);
+        const col = c.p.keyboardColumn(c.p.active) orelse return;
+        if (col + 1 >= c.p.ncol) return c.p.reportFailure(c.id, "Joincol: no column to the right");
+        layout.joinCol(c.p, col);
     }
 };
 
@@ -1059,8 +1062,8 @@ pub const Tutor = struct {
     pub const scope: Scope = .session;
     pub fn run(c: Ctx) void {
         const free = c.p.freeSlot() orelse return;
-        const nt = c.p.openTutorView(free) catch return;
-        exec.placeDoc(c.p, c.id, free, nt); // a doc like any other
+        _ = c.p.openTutorView(free) catch return;
+        exec.placeNew(c.p, c.id, c.id, free, .doc); // a doc like any other
     }
 };
 
@@ -1221,8 +1224,10 @@ pub const Down = struct {
                 return tagline.enterHeader(c.p, if (column) |at| at.col else 0);
             // Onto the top pane of the column the header stands over.
             const col = c.p.header_column orelse if (column) |at| at.col else return;
+            // An empty column's tag has nothing below it.
+            if (col < c.p.ncol and c.p.col_n[col] == 0) return;
             tagline.exitHeader(c.p);
-            if (col < c.p.ncol and c.p.col_n[col] > 0) c.p.active = c.p.col_panes[col][0];
+            if (col < c.p.ncol) c.p.active = c.p.col_panes[col][0];
             return;
         }
         _ = layout.focusDir(c.p, c.id, .down);