A GUI-only setting says so on a terminal, and DumpDir reads back its directory

`Lift on` over ctl on a terminal answered "unknown control message" while
Config listed Lift as unsupported, and the ctl's DumpDir line read bare while
Config showed the path in effect. A setting word this frontend lacks is now
refused as `Lift is GUI-only` (GripWidth too), and DumpDir reads back the
directory in effect, as Config does.

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

1 files changed, 32 insertions, 2 deletions

diff --git a/src/ninep/ctl.zig b/src/ninep/ctl.zig
index caf8914f..4faa7df7 100644
--- a/src/ninep/ctl.zig
+++ b/src/ninep/ctl.zig
@@ -259,7 +259,15 @@ fn checkBuiltin(p: *Pardes, req: Req, line: []const u8, scope: builtins.Scope) ?
     const sp = std.mem.indexOfAny(u8, line, " \t");
     const word = line[0 .. sp orelse line.len];
     const arg = if (sp) |s| std.mem.trim(u8, line[s + 1 ..], " \t") else "";
-    const b = std.meta.stringToEnum(Builtin, word) orelse return refuse(p, req, "unknown control message", line);
+    const b = std.meta.stringToEnum(Builtin, word) orelse {
+        // A setting this build's frontend cannot show (Lift, GripWidth on a
+        // terminal) is known, and says so rather than sound misspelt.
+        if (config.Runtime.find(word) != null) {
+            var why: [64]u8 = undefined;
+            return refuse(p, req, std.fmt.bufPrint(&why, "{s} is GUI-only", .{word}) catch "GUI-only", line);
+        }
+        return refuse(p, req, "unknown control message", line);
+    };
     // Edit is the one pane word the root takes too: at the active pane.
     if (builtins.registry.scope(b) != scope and b != .Edit)
         return refuseTo(p, req, if (scope == .pane) "not a window control message" else "not a session control message", line, if (scope == .pane) "/ctl" else "pane/<n>/ctl");
@@ -353,7 +361,12 @@ fn writeSettings(p: *Pardes, w: *std.Io.Writer) !void {
             },
             .message_ms => |which| try w.print("{s} {d}\n", .{ word, @field(s, "message_" ++ @tagName(which) ++ "_ms") }),
             // Bare, it names the default directory.
-            .dump_dir => if (s.dump_dir.len > 0) try w.print("{s} {s}\n", .{ word, s.dump_dir.get() }) else try w.print("{s}\n", .{word}),
+            // The directory in effect, as Config reports it; bare only when
+            // there is none (no home to put the default in).
+            .dump_dir => {
+                var buf: [900]u8 = undefined;
+                if (pardes.dump.directory(&buf, s.dump_dir.get())) |dir| try w.print("{s} {s}\n", .{ word, dir }) else try w.print("{s}\n", .{word});
+            },
             .transition => |effect| try w.print("{s} {s}\n", .{ word, if (s.panel_transition == effect) "on" else "off" }),
             .scene => |effect| if (s.post.level(effect) == 0) try w.print("{s} off\n", .{word}) else try w.print("{s} {d}\n", .{ word, s.post.level(effect) }),
             .shader => for (s.post.list()) |entry| if (entry.scene == null) try w.print("{s} {s}\n", .{ word, entry.path.get() }),
@@ -1264,3 +1277,20 @@ test "a Restore of a file that is no dump fails the write before any warning, an
     p.dumpFailed("/nowhere/pardes.dump.zon", error.FileNotFound);
     try testing.expectEqualStrings("Dump /nowhere/pardes.dump.zon: FileNotFound", p.fs.late_failure[0..p.fs.late_failure_len]);
 }
+
+test "a setting this frontend cannot show says GUI-only, and DumpDir reads back the directory in effect" {
+    const p = try withFile(testing.allocator, "x\n");
+    defer p.deinit();
+    const root_ctl = @intFromEnum(tree.TopFile.ctl);
+    if (!builtins.capabilities.lift) {
+        try testing.expectEqualStrings("Lift is GUI-only \"Lift on\"", wr(p, root_ctl, "Lift on\n").reply.ename);
+        try testing.expectEqualStrings("GripWidth is GUI-only \"GripWidth 120\"", wr(p, root_ctl, "GripWidth 120\n").reply.ename);
+    }
+    try testing.expectEqualStrings("unknown control message \"Liftt on\"", wr(p, root_ctl, "Liftt on\n").reply.ename);
+    var buf: [900]u8 = undefined;
+    if (pardes.dump.directory(&buf, "")) |dir| {
+        var want: [920]u8 = undefined;
+        const line = try std.fmt.bufPrint(&want, "\nDumpDir {s}\n", .{dir});
+        try testing.expect(std.mem.indexOf(u8, rd(p, root_ctl, 0, 1 << 16).bytes, line) != null);
+    }
+}