From 673403f950ee6198956c03c24989438de2e95a4e Mon Sep 17 00:00:00 2001
From: Muki Kiboigo <muki@muki.gg>
Date: Mon, 25 May 2026 12:31:37 -0700
Subject: [PATCH] properly flush frame after syncRequest eval

---
 src/browser/ScriptManager.zig        |  3 ++
 src/browser/ScriptManagerBase.zig    | 11 -------
 src/network/layer/DeferringLayer.zig | 48 ++++++++++++++++++++++++++--
 3 files changed, 49 insertions(+), 13 deletions(-)

diff --git a/src/browser/ScriptManager.zig b/src/browser/ScriptManager.zig
index 6d5d5dfd..b5f41eca 100644
--- a/src/browser/ScriptManager.zig
+++ b/src/browser/ScriptManager.zig
@@ -288,6 +288,9 @@ pub fn addFromElement(self: *ScriptManager, comptime from_parser: bool, script_e
         return;
     }
 
+    // This will flush any deferred scripts.
+    defer self.base.client.deferring_layer.flushFrame(self.base.owner.frameId());
+
     if (script.status < 200 or script.status > 299) {
         log.info(.http, "script load error", .{ .status = script.status });
         script.executeCallback(comptime .wrap("error"));
diff --git a/src/browser/ScriptManagerBase.zig b/src/browser/ScriptManagerBase.zig
index 6a437534..6c72fa7a 100644
--- a/src/browser/ScriptManagerBase.zig
+++ b/src/browser/ScriptManagerBase.zig
@@ -390,17 +390,6 @@ pub fn staticScriptsDone(self: *ScriptManagerBase) void {
     lp.assert(self.static_scripts_done == false, "ScriptManagerBase.staticScriptsDone", .{});
     self.static_scripts_done = true;
 
-    const frame_id = self.owner.frameId();
-    if (comptime IS_DEBUG) {
-        const blocking_request_id = self.client.blocking_requests.get(frame_id);
-        lp.assert(
-            blocking_request_id == null,
-            "there should be no blocking request on this frame",
-            .{ .value = blocking_request_id },
-        );
-    }
-    self.client.deferring_layer.flushFrame(frame_id);
-
     self.evaluate();
 }
 
diff --git a/src/network/layer/DeferringLayer.zig b/src/network/layer/DeferringLayer.zig
index 73ae9cf5..018212e3 100644
--- a/src/network/layer/DeferringLayer.zig
+++ b/src/network/layer/DeferringLayer.zig
@@ -102,12 +102,17 @@ pub fn flushFrame(self: *DeferringLayer, frame_id: u32) void {
     while (node) |n| {
         node = n.next;
         const ctx: *DeferredContext = @fieldParentPtr("node", n);
-        if (!ctx.deferring or !ctx.terminal) continue;
+        if (!ctx.deferring) continue;
 
         const deferred_req = ctx.transfer.req;
-        if (deferred_req.frame_id == frame_id) {
+        if (deferred_req.frame_id != frame_id) continue;
+
+        if (ctx.terminal) {
             self.active.remove(n);
             ctx.fire();
+        } else {
+            ctx.firePartial();
+            ctx.deferring = false;
         }
     }
 }
@@ -296,4 +301,43 @@ const DeferredContext = struct {
             }
         }
     }
+
+    fn firePartial(self: *DeferredContext) void {
+        const req = self.transfer.req;
+        const stable_response = self.stable_resp orelse return;
+        const response = Response.fromStable(&stable_response);
+
+        for (self.buffered.items) |event| {
+            switch (event) {
+                .start => {
+                    self.forward.forwardStart(response) catch |err| {
+                        log.err(.http, "defer part start callback", .{ .err = err, .url = req.url });
+                        self.forward.forwardErr(err);
+                        return;
+                    };
+                },
+                .header => {
+                    const proceed = self.forward.forwardHeader(response) catch |err| {
+                        log.err(.http, "defer part header callback", .{ .err = err, .url = req.url });
+                        self.forward.forwardErr(err);
+                        return;
+                    };
+                    if (!proceed) {
+                        self.forward.forwardErr(error.Abort);
+                        return;
+                    }
+                },
+                .data => |chunk| {
+                    self.forward.forwardData(response, chunk) catch |err| {
+                        log.err(.http, "defer part data callback", .{ .err = err, .url = req.url });
+                        self.forward.forwardErr(err);
+                        return;
+                    };
+                },
+                .done, .err, .shutdown => @panic("firePartial cant fire terminal events"),
+            }
+        }
+
+        self.buffered.clearRetainingCapacity();
+    }
 };