1 files changed, 31 insertions, 2 deletions

diff --git a/src/detached/client.zig b/src/detached/client.zig
index 8c9a2560..69ab2fdd 100644
--- a/src/detached/client.zig
+++ b/src/detached/client.zig
@@ -109,6 +109,10 @@ pub const Client = struct {
     regions: std.ArrayListUnmanaged(pardes.Region) = .empty,
     /// The palette its chrome is drawn in, as its last frame gave it.
     chrome: pardes.Chrome = .{},
+    /// The post chain its frames are drawn through, as the session last
+    /// sent it; its paths and SPIR-V owned here. `post_key` moves with it.
+    post: wire.Post = .{},
+    post_key: u32 = 0,
     in: std.ArrayListUnmanaged(u8) = .empty,
     out: std.ArrayListUnmanaged(u8) = .empty,
     /// Bytes of `in` belonging to the message `next` returned last. Compacted at
@@ -187,6 +191,7 @@ pub const Client = struct {
         }
         for (&c.tag_layers) |*layer| c.gpa.free(layer.cells);
         c.regions.deinit(c.gpa);
+        c.freePost();
         c.in.deinit(c.gpa);
         c.out.deinit(c.gpa);
     }
@@ -356,10 +361,30 @@ pub const Client = struct {
             // open a URI on this display or read this display's selection back
             // over the socket. `Ungreeted` is the same refusal a frame gets.
             .set_clipboard, .read_clipboard, .open_link => if (!c.attached()) return error.Ungreeted,
+            // Kept, like the chrome: the frames that follow are drawn
+            // through it.
+            .post => |chain| {
+                if (!c.attached()) return error.Ungreeted;
+                c.freePost();
+                c.post = chain;
+                for (c.post.passes[0..c.post.len]) |*pass| {
+                    pass.path = c.gpa.dupe(u8, pass.path) catch return error.Closed;
+                    pass.spirv = c.gpa.dupe(u8, pass.spirv) catch return error.Closed;
+                }
+                c.post_key +%= 1;
+            },
         }
         return msg;
     }
 
+    fn freePost(c: *Client) void {
+        for (c.post.passes[0..c.post.len]) |pass| {
+            c.gpa.free(pass.path);
+            c.gpa.free(pass.spirv);
+        }
+        c.post = .{};
+    }
+
     // ---- internals --------------------------------------------------------
 
     fn reshape(c: *Client, cols: u16, rows: u16) (Error || wire.Error)!void {
@@ -1131,7 +1156,7 @@ test "detached session: the seam's own routing rules, per surviving effect" {
 test "detached session: a frontend is never asked to fork, write, or watch" {
     // THE INVARIANT OF THE WHOLE DETACHED DESIGN, pinned as a property of the
     // protocol rather than of one code path: a frontend is input and screen, so
-    // the set of messages that can reach it is exactly the eight below. If a
+    // the set of messages that can reach it is exactly the nine below. If a
     // machine-local effect is ever put back on the wire, a frontend becomes the
     // process that owns a pane's shell again — and a pane whose shell belongs to
     // a frontend dies when that frontend leaves, which is the bug this replaced.
@@ -1149,6 +1174,10 @@ test "detached session: a frontend is never asked to fork, write, or watch" {
         // The three that need THIS human's display and cannot be done by a
         // daemon nobody is looking at.
         "set_clipboard", "read_clipboard", "open_link",
+        // Display state, like a frame's chrome: the passes this display
+        // draws its frames through. A file's SPIR-V arrives compiled, so the
+        // frontend still reads no disk and runs no program.
+        "post",
     };
 
     // One: the union a frontend decodes into has no other variant. Named
@@ -1183,7 +1212,7 @@ test "detached session: a frontend is never asked to fork, write, or watch" {
             if (@intFromEnum(want) == tag) break true;
         } else false;
         if (!named) {
-            std.debug.print("tag 0x{x:0>2} is decodable by a frontend and is not one of the seven\n", .{tag});
+            std.debug.print("tag 0x{x:0>2} is decodable by a frontend and is not one of the nine\n", .{tag});
             return error.MachineLocalEffectOnTheWire;
         }
     }