From 963ff338c081fe3d445e8f475d1f305194fd63d3 Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 09:44:42 -0500
Subject: [PATCH 01/11] Add additional scoping for head buffering

---
 packages/astro/src/content/internal.ts        |  3 +-
 packages/astro/src/runtime/server/index.ts    |  1 +
 packages/astro/src/runtime/server/jsx.ts      |  7 +++--
 .../runtime/server/render/astro/factory.ts    |  6 ++--
 .../runtime/server/render/astro/instance.ts   |  2 ++
 .../astro/src/runtime/server/render/head.ts   |  8 +++--
 .../astro/src/runtime/server/render/index.ts  |  1 +
 .../astro/src/runtime/server/render/page.ts   |  3 ++
 .../astro/src/runtime/server/render/scope.ts  | 31 +++++++++++++++++++
 .../astro/src/runtime/server/render/slot.ts   |  7 +++--
 .../astro/src/runtime/server/render/util.ts   |  6 ----
 .../mdx/test/css-head-mdx.test.js             |  8 +++++
 .../src/components/SmallCaps.astro            |  3 ++
 .../css-head-mdx/src/content/posts/test.mdx   |  5 +++
 .../src/layouts/ContentLayout.astro           | 24 ++++++++++++++
 .../css-head-mdx/src/pages/posts/[post].astro | 18 +++++++++++
 .../css-head-mdx/src/styles/global.css        |  3 ++
 17 files changed, 118 insertions(+), 18 deletions(-)
 create mode 100644 packages/astro/src/runtime/server/render/scope.ts
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/SmallCaps.astro
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/posts/test.mdx
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/layouts/ContentLayout.astro
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/posts/[post].astro
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/styles/global.css

diff --git a/packages/astro/src/content/internal.ts b/packages/astro/src/content/internal.ts
index 04280166feb3..ebfb971be44a 100644
--- a/packages/astro/src/content/internal.ts
+++ b/packages/astro/src/content/internal.ts
@@ -4,6 +4,7 @@ import { prependForwardSlash } from '../core/path.js';
 import {
 	createComponent,
 	createHeadAndContent,
+	createScopedResult,
 	renderComponent,
 	renderScriptElement,
 	renderStyleElement,
@@ -169,7 +170,7 @@ async function render({
 
 			return createHeadAndContent(
 				unescapeHTML(styles + links + scripts) as any,
-				renderTemplate`${renderComponent(result, 'Content', mod.Content, props, slots)}`
+				renderTemplate`${renderComponent(createScopedResult(result), 'Content', mod.Content, props, slots)}`
 			);
 		},
 		propagation: 'self',
diff --git a/packages/astro/src/runtime/server/index.ts b/packages/astro/src/runtime/server/index.ts
index ccdfd5e1968f..b548b029e117 100644
--- a/packages/astro/src/runtime/server/index.ts
+++ b/packages/astro/src/runtime/server/index.ts
@@ -6,6 +6,7 @@ export { renderJSX } from './jsx.js';
 export {
 	addAttribute,
 	createHeadAndContent,
+	createScopedResult,
 	defineScriptVars,
 	Fragment,
 	maybeRenderHead,
diff --git a/packages/astro/src/runtime/server/jsx.ts b/packages/astro/src/runtime/server/jsx.ts
index 8b81a641ea35..665e4afec8fb 100644
--- a/packages/astro/src/runtime/server/jsx.ts
+++ b/packages/astro/src/runtime/server/jsx.ts
@@ -12,7 +12,7 @@ import {
 } from './index.js';
 import { HTMLParts } from './render/common.js';
 import type { ComponentIterable } from './render/component';
-import { ScopeFlags } from './render/util.js';
+import { createScopedResult, ScopeFlags } from './render/scope.js';
 
 const ClientOnlyPlaceholder = 'astro-client-only';
 
@@ -95,8 +95,9 @@ Did you forget to import the component or is it possible there is a typo?`);
 						props[key] = value;
 					}
 				}
-				result.scope |= ScopeFlags.JSX;
-				return markHTMLString(await renderToString(result, vnode.type as any, props, slots));
+				const scoped = createScopedResult(result, ScopeFlags.JSX);
+				const html = markHTMLString(await renderToString(scoped, vnode.type as any, props, slots));
+				return html;
 			}
 			case !vnode.type && (vnode.type as any) !== 0:
 				return '';
diff --git a/packages/astro/src/runtime/server/render/astro/factory.ts b/packages/astro/src/runtime/server/render/astro/factory.ts
index 1f85fe45c72f..7f5b912472ef 100644
--- a/packages/astro/src/runtime/server/render/astro/factory.ts
+++ b/packages/astro/src/runtime/server/render/astro/factory.ts
@@ -3,7 +3,7 @@ import type { HeadAndContent } from './head-and-content';
 import type { RenderTemplateResult } from './render-template';
 
 import { HTMLParts } from '../common.js';
-import { ScopeFlags } from '../util.js';
+import { addScopeFlag, createScopedResult, ScopeFlags } from '../scope.js';
 import { isHeadAndContent } from './head-and-content.js';
 import { renderAstroTemplateResult } from './render-template.js';
 
@@ -28,8 +28,8 @@ export async function renderToString(
 	props: any,
 	children: any
 ): Promise<string> {
-	result.scope |= ScopeFlags.Astro;
-	const factoryResult = await componentFactory(result, props, children);
+	const scoped = createScopedResult(result, ScopeFlags.Astro);
+	const factoryResult = await componentFactory(scoped, props, children);
 
 	if (factoryResult instanceof Response) {
 		const response = factoryResult;
diff --git a/packages/astro/src/runtime/server/render/astro/instance.ts b/packages/astro/src/runtime/server/render/astro/instance.ts
index d290abcc1640..c330b1319f90 100644
--- a/packages/astro/src/runtime/server/render/astro/instance.ts
+++ b/packages/astro/src/runtime/server/render/astro/instance.ts
@@ -7,6 +7,7 @@ import { isPromise } from '../../util.js';
 import { renderChild } from '../any.js';
 import { isAPropagatingComponent } from './factory.js';
 import { isHeadAndContent } from './head-and-content.js';
+import { addScopeFlag, removeScopeFlag, ScopeFlags } from '../scope.js';
 
 type ComponentProps = Record<string | number, any>;
 type ComponentSlotValue = () => ReturnType<typeof renderTemplate>;
@@ -33,6 +34,7 @@ export class AstroComponentInstance {
 		this.props = props;
 		this.factory = factory;
 		this.slotValues = {};
+		addScopeFlag(result, ScopeFlags.Slot);
 		for (const name in slots) {
 			this.slotValues[name] = slots[name]();
 		}
diff --git a/packages/astro/src/runtime/server/render/head.ts b/packages/astro/src/runtime/server/render/head.ts
index 0f39fe2192a8..e3a4ae9aa9f7 100644
--- a/packages/astro/src/runtime/server/render/head.ts
+++ b/packages/astro/src/runtime/server/render/head.ts
@@ -1,7 +1,8 @@
 import type { SSRResult } from '../../../@types/astro';
 
 import { markHTMLString } from '../escape.js';
-import { renderElement, ScopeFlags } from './util.js';
+import { renderElement } from './util.js';
+import { ScopeFlags } from './scope.js';
 
 // Filter out duplicate elements in our set
 const uniqueElements = (item: any, index: number, all: any[]) => {
@@ -55,10 +56,13 @@ export function* maybeRenderHead(result: SSRResult) {
 	// Don't render the head inside of a JSX component that's inside of an Astro component
 	// as the Astro component will be the one to render the head.
 	switch (result.scope) {
-		case ScopeFlags.JSX | ScopeFlags.Slot | ScopeFlags.Astro: {
+		case ScopeFlags.JSX | ScopeFlags.Slot | ScopeFlags.Astro:
+		// TODO Explain
+		case ScopeFlags.JSX | ScopeFlags.Astro | ScopeFlags.HeadBuffer: {
 			return;
 		}
 	}
+	
 
 	// This is an instruction informing the page rendering that head might need rendering.
 	// This allows the page to deduplicate head injections.
diff --git a/packages/astro/src/runtime/server/render/index.ts b/packages/astro/src/runtime/server/render/index.ts
index 012b421f5784..1ec38ee6e598 100644
--- a/packages/astro/src/runtime/server/render/index.ts
+++ b/packages/astro/src/runtime/server/render/index.ts
@@ -16,6 +16,7 @@ export { renderHTMLElement } from './dom.js';
 export { maybeRenderHead, renderHead } from './head.js';
 export { renderPage } from './page.js';
 export { renderSlot } from './slot.js';
+export { createScopedResult } from './scope.js';
 export { renderScriptElement, renderStyleElement, renderUniqueStylesheet } from './tags.js';
 export type { RenderInstruction } from './types';
 export { addAttribute, defineScriptVars, voidElementNames } from './util.js';
diff --git a/packages/astro/src/runtime/server/render/page.ts b/packages/astro/src/runtime/server/render/page.ts
index b949019d6967..8ae2969f5841 100644
--- a/packages/astro/src/runtime/server/render/page.ts
+++ b/packages/astro/src/runtime/server/render/page.ts
@@ -15,6 +15,7 @@ import {
 import { chunkToByteArray, encoder, HTMLParts } from './common.js';
 import { renderComponent } from './component.js';
 import { maybeRenderHead } from './head.js';
+import { addScopeFlag, removeScopeFlag, ScopeFlags } from './scope.js';
 
 const needsHeadRenderingSymbol = Symbol.for('astro.needsHeadRendering');
 
@@ -55,6 +56,7 @@ async function iterableToHTMLBytes(
 // to be propagated up.
 async function bufferHeadContent(result: SSRResult) {
 	const iterator = result.propagators.values();
+	addScopeFlag(result, ScopeFlags.HeadBuffer);
 	while (true) {
 		const { value, done } = iterator.next();
 		if (done) {
@@ -65,6 +67,7 @@ async function bufferHeadContent(result: SSRResult) {
 			result.extraHead.push(returnValue.head);
 		}
 	}
+	removeScopeFlag(result, ScopeFlags.HeadBuffer);
 }
 
 export async function renderPage(
diff --git a/packages/astro/src/runtime/server/render/scope.ts b/packages/astro/src/runtime/server/render/scope.ts
new file mode 100644
index 000000000000..458ed19a33dc
--- /dev/null
+++ b/packages/astro/src/runtime/server/render/scope.ts
@@ -0,0 +1,31 @@
+import type { SSRResult } from '../../../@types/astro';
+
+export const ScopeFlags = {
+	Astro: 1 << 0, // 1
+	JSX: 1 << 1, // 2
+	Slot: 1 << 2, // 4
+	HeadBuffer: 1 << 3, // 8
+} as const;
+
+type ScopeFlagValues = (typeof ScopeFlags)[keyof typeof ScopeFlags];
+
+export function addScopeFlag(result: SSRResult, flag: ScopeFlagValues) {
+	result.scope |= flag;
+}
+
+export function removeScopeFlag(result: SSRResult, flag: ScopeFlagValues) {
+	result.scope &= ~flag;
+}
+
+export function createScopedResult(result: SSRResult, flag?: ScopeFlagValues): SSRResult {
+	const scopedResult =  Object.create(result, {
+		scope: {
+			writable: true,
+			value: result.scope
+		}
+	});
+	if(flag != null) {
+		addScopeFlag(scopedResult, flag);
+	}
+	return scopedResult;
+}
diff --git a/packages/astro/src/runtime/server/render/slot.ts b/packages/astro/src/runtime/server/render/slot.ts
index 32d0a2dc1299..c119bea8f5d7 100644
--- a/packages/astro/src/runtime/server/render/slot.ts
+++ b/packages/astro/src/runtime/server/render/slot.ts
@@ -3,7 +3,7 @@ import type { RenderInstruction } from './types.js';
 
 import { HTMLString, markHTMLString } from '../escape.js';
 import { renderChild } from './any.js';
-import { ScopeFlags } from './util.js';
+import { ScopeFlags, addScopeFlag, removeScopeFlag } from './scope.js';
 
 const slotString = Symbol.for('astro:slot-string');
 
@@ -27,7 +27,7 @@ export async function renderSlot(
 	fallback?: any
 ): Promise<string> {
 	if (slotted) {
-		result.scope |= ScopeFlags.Slot;
+		addScopeFlag(result, ScopeFlags.Slot);
 		let iterator = renderChild(slotted);
 		let content = '';
 		let instructions: null | RenderInstruction[] = null;
@@ -42,7 +42,8 @@ export async function renderSlot(
 			}
 		}
 		// Remove the flag since we are now outside of the scope.
-		result.scope &= ~ScopeFlags.Slot;
+		removeScopeFlag(result, ScopeFlags.Slot);
+		
 		return markHTMLString(new SlotString(content, instructions));
 	}
 	return fallback;
diff --git a/packages/astro/src/runtime/server/render/util.ts b/packages/astro/src/runtime/server/render/util.ts
index 7e5ca9a5d160..a95ef16f8722 100644
--- a/packages/astro/src/runtime/server/render/util.ts
+++ b/packages/astro/src/runtime/server/render/util.ts
@@ -128,9 +128,3 @@ export function renderElement(
 	}
 	return `<${name}${internalSpreadAttributes(props, shouldEscape)}>${children}</${name}>`;
 }
-
-export const ScopeFlags = {
-	Astro: 1 << 0,
-	JSX: 1 << 1,
-	Slot: 1 << 2,
-};
diff --git a/packages/integrations/mdx/test/css-head-mdx.test.js b/packages/integrations/mdx/test/css-head-mdx.test.js
index 2b1dcdfe7bcd..0c4afda1fc50 100644
--- a/packages/integrations/mdx/test/css-head-mdx.test.js
+++ b/packages/integrations/mdx/test/css-head-mdx.test.js
@@ -29,5 +29,13 @@ describe('Head injection w/ MDX', () => {
 			const scripts = document.querySelectorAll('head script[type=module]');
 			expect(scripts).to.have.a.lengthOf(1);
 		});
+
+		it('injects into the head for content collections', async () => {
+			const html = await fixture.readFile('/posts/test/index.html');
+			const { document } = parseHTML(html);
+
+			const links = document.querySelectorAll('head link[rel=stylesheet]');
+			expect(links).to.have.a.lengthOf(1);
+		});
 	});
 });
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/SmallCaps.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/SmallCaps.astro
new file mode 100644
index 000000000000..a0bd6e1f1501
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/SmallCaps.astro
@@ -0,0 +1,3 @@
+---
+---
+<span style={{fontVariant: "small-caps"}}><slot /></span>
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/posts/test.mdx b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/posts/test.mdx
new file mode 100644
index 000000000000..0bb1153cab7c
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/posts/test.mdx
@@ -0,0 +1,5 @@
+---
+title: Testing
+---
+
+<SmallCaps>A test file</SmallCaps>
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/layouts/ContentLayout.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/layouts/ContentLayout.astro
new file mode 100644
index 000000000000..7b234e86859a
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/layouts/ContentLayout.astro
@@ -0,0 +1,24 @@
+---
+export interface Props {
+	title: string;
+}
+
+const { title } = Astro.props;
+---
+
+<!DOCTYPE html>
+<html lang="en">
+	<head>
+		<meta charset="UTF-8" />
+		<meta name="viewport" content="width=device-width" />
+		<link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+		<meta name="generator" content={Astro.generator} />
+		<title>{title}</title>
+		<style is:global>
+			@import "../styles/global.css";
+		</style>
+	</head>
+	<body>
+		<slot />
+	</body>
+</html>
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/posts/[post].astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/posts/[post].astro
new file mode 100644
index 000000000000..7d6ca0ca4d37
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/posts/[post].astro
@@ -0,0 +1,18 @@
+---
+import { getCollection } from 'astro:content';
+import Layout from '../../layouts/ContentLayout.astro';
+import SmallCaps from '../../components/SmallCaps.astro';
+
+export async function getStaticPaths() {
+  const entries = await getCollection('posts');
+  return entries.map(entry => {
+    return {params: { post: entry.slug }, props: { entry },
+  }});
+}
+
+const { entry } = Astro.props;
+const { Content } = await entry.render();
+---
+<Layout title="">
+  <Content components={{ SmallCaps }} />
+</Layout>
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/styles/global.css b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/styles/global.css
new file mode 100644
index 000000000000..e1450526f7a2
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/styles/global.css
@@ -0,0 +1,3 @@
+html {
+	font-weight: bolder;
+}

From e27b5c5d2fdddb3703d482e797b2aa66c0b8d9a0 Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 11:28:28 -0500
Subject: [PATCH 02/11] Add test for direct usage of nested component

---
 .../integrations/mdx/test/css-head-mdx.test.js  | 12 ++++++++++++
 .../css-head-mdx/src/components/UsingMdx.astro  | 10 ++++++++++
 .../src/components/WithHoistedScripts.astro     |  6 ++++++
 .../css-head-mdx/src/content/blog/_styles.css   |  3 +++
 .../css-head-mdx/src/content/blog/using-mdx.mdx |  6 ++++++
 .../src/pages/DirectContentUsage.astro          | 17 +++++++++++++++++
 6 files changed, 54 insertions(+)
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/WithHoistedScripts.astro
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/_styles.css
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/using-mdx.mdx
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/DirectContentUsage.astro

diff --git a/packages/integrations/mdx/test/css-head-mdx.test.js b/packages/integrations/mdx/test/css-head-mdx.test.js
index 0c4afda1fc50..f75892f7baba 100644
--- a/packages/integrations/mdx/test/css-head-mdx.test.js
+++ b/packages/integrations/mdx/test/css-head-mdx.test.js
@@ -37,5 +37,17 @@ describe('Head injection w/ MDX', () => {
 			const links = document.querySelectorAll('head link[rel=stylesheet]');
 			expect(links).to.have.a.lengthOf(1);
 		});
+
+		it.skip('injects content from a component using Content#render()', async () => {
+			const html = await fixture.readFile('/DirectContentUsage/index.html');
+			console.log(html);
+			const { document } = parseHTML(html);
+
+			const links = document.querySelectorAll('head link[rel=stylesheet]');
+			expect(links).to.have.a.lengthOf(1);
+
+			const scripts = document.querySelectorAll('head script[type=module]');
+			expect(scripts).to.have.a.lengthOf(1);
+		});
 	});
 });
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro
new file mode 100644
index 000000000000..defbad800219
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro
@@ -0,0 +1,10 @@
+---
+import { getEntryBySlug } from 'astro:content';
+
+const launchWeek = await getEntryBySlug('blog', 'using-mdx');
+const { Content } = await launchWeek.render();
+
+debugger;
+---
+
+<Content />
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/WithHoistedScripts.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/WithHoistedScripts.astro
new file mode 100644
index 000000000000..0b8c4445f6fd
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/WithHoistedScripts.astro
@@ -0,0 +1,6 @@
+---
+---
+
+<script>
+	console.log('hoisted')
+	</script>
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/_styles.css b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/_styles.css
new file mode 100644
index 000000000000..1379b29c06f0
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/_styles.css
@@ -0,0 +1,3 @@
+body {
+  color: red !important;
+}
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/using-mdx.mdx b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/using-mdx.mdx
new file mode 100644
index 000000000000..917fc3331288
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/content/blog/using-mdx.mdx
@@ -0,0 +1,6 @@
+import './_styles.css';
+import WithHoistedScripts from '../../components/WithHoistedScripts.astro';
+
+# Using mdx
+
+<WithHoistedScripts />
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/DirectContentUsage.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/DirectContentUsage.astro
new file mode 100644
index 000000000000..cbf4295a7149
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/DirectContentUsage.astro
@@ -0,0 +1,17 @@
+---
+import UsingMdx from '../components/UsingMdx.astro'
+---
+
+<html lang="en">
+	<head>
+		<meta charset="utf-8" />
+		<link rel="icon" type="image/svg+xml" href="/favicon.svg" />
+		<meta name="viewport" content="width=device-width" />
+		<meta name="generator" content={Astro.generator} />
+		<title>Astro</title>
+	</head>
+	<body>
+		<h1>Astro</h1>
+		<UsingMdx />
+	</body>
+</html>

From 9bf34efd7ca8fdc40f5a1998cba472ca63d81eeb Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 12:03:24 -0500
Subject: [PATCH 03/11] Add special scoping for Astro.scopes.render()

---
 packages/astro/src/core/render/result.ts      |  3 +-
 packages/astro/src/runtime/server/index.ts    |  3 ++
 .../astro/src/runtime/server/render/head.ts   |  5 +++-
 .../astro/src/runtime/server/render/index.ts  |  2 +-
 .../astro/src/runtime/server/render/scope.ts  |  1 +
 .../mdx/test/css-head-mdx.test.js             |  8 ++++++
 .../test/fixtures/css-head-mdx/package.json   | 10 +++++++
 .../css-head-mdx/src/components/P.astro       |  3 ++
 .../src/components/UsingMdx.astro             |  2 --
 .../css-head-mdx/src/pages/remote.astro       | 17 +++++++++++
 pnpm-lock.yaml                                | 28 +++++++++++++++++++
 11 files changed, 77 insertions(+), 5 deletions(-)
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/package.json
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/P.astro
 create mode 100644 packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/remote.astro

diff --git a/packages/astro/src/core/render/result.ts b/packages/astro/src/core/render/result.ts
index 3a6b0bf964d6..ea360d8baff9 100644
--- a/packages/astro/src/core/render/result.ts
+++ b/packages/astro/src/core/render/result.ts
@@ -9,7 +9,7 @@ import type {
 	SSRLoadedRenderer,
 	SSRResult,
 } from '../../@types/astro';
-import { renderSlot, stringifyChunk } from '../../runtime/server/index.js';
+import { addScopeFlag, renderSlot, stringifyChunk, ScopeFlags } from '../../runtime/server/index.js';
 import { renderJSX } from '../../runtime/server/jsx.js';
 import { AstroCookies } from '../cookies/index.js';
 import { AstroError, AstroErrorData } from '../errors/index.js';
@@ -89,6 +89,7 @@ class Slots {
 	public async render(name: string, args: any[] = []) {
 		if (!this.#slots || !this.has(name)) return;
 
+		addScopeFlag(this.#result, ScopeFlags.RenderSlot);
 		if (!Array.isArray(args)) {
 			warn(
 				this.#loggingOpts,
diff --git a/packages/astro/src/runtime/server/index.ts b/packages/astro/src/runtime/server/index.ts
index b548b029e117..ba5c32d22c5a 100644
--- a/packages/astro/src/runtime/server/index.ts
+++ b/packages/astro/src/runtime/server/index.ts
@@ -5,11 +5,13 @@ export { escapeHTML, HTMLBytes, HTMLString, markHTMLString, unescapeHTML } from
 export { renderJSX } from './jsx.js';
 export {
 	addAttribute,
+	addScopeFlag,
 	createHeadAndContent,
 	createScopedResult,
 	defineScriptVars,
 	Fragment,
 	maybeRenderHead,
+	removeScopeFlag,
 	renderAstroTemplateResult as renderAstroComponent,
 	renderComponent,
 	renderComponentToIterable,
@@ -24,6 +26,7 @@ export {
 	renderTemplate,
 	renderToString,
 	renderUniqueStylesheet,
+	ScopeFlags,
 	stringifyChunk,
 	voidElementNames,
 } from './render/index.js';
diff --git a/packages/astro/src/runtime/server/render/head.ts b/packages/astro/src/runtime/server/render/head.ts
index e3a4ae9aa9f7..ca4c17de362d 100644
--- a/packages/astro/src/runtime/server/render/head.ts
+++ b/packages/astro/src/runtime/server/render/head.ts
@@ -61,8 +61,11 @@ export function* maybeRenderHead(result: SSRResult) {
 		case ScopeFlags.JSX | ScopeFlags.Astro | ScopeFlags.HeadBuffer: {
 			return;
 		}
+		case ScopeFlags.RenderSlot | ScopeFlags.Astro:
+		case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX: {
+			return;
+		}
 	}
-	
 
 	// This is an instruction informing the page rendering that head might need rendering.
 	// This allows the page to deduplicate head injections.
diff --git a/packages/astro/src/runtime/server/render/index.ts b/packages/astro/src/runtime/server/render/index.ts
index 1ec38ee6e598..1686300ccb22 100644
--- a/packages/astro/src/runtime/server/render/index.ts
+++ b/packages/astro/src/runtime/server/render/index.ts
@@ -16,7 +16,7 @@ export { renderHTMLElement } from './dom.js';
 export { maybeRenderHead, renderHead } from './head.js';
 export { renderPage } from './page.js';
 export { renderSlot } from './slot.js';
-export { createScopedResult } from './scope.js';
+export { createScopedResult, ScopeFlags, addScopeFlag, removeScopeFlag } from './scope.js';
 export { renderScriptElement, renderStyleElement, renderUniqueStylesheet } from './tags.js';
 export type { RenderInstruction } from './types';
 export { addAttribute, defineScriptVars, voidElementNames } from './util.js';
diff --git a/packages/astro/src/runtime/server/render/scope.ts b/packages/astro/src/runtime/server/render/scope.ts
index 458ed19a33dc..fb40d40f1675 100644
--- a/packages/astro/src/runtime/server/render/scope.ts
+++ b/packages/astro/src/runtime/server/render/scope.ts
@@ -5,6 +5,7 @@ export const ScopeFlags = {
 	JSX: 1 << 1, // 2
 	Slot: 1 << 2, // 4
 	HeadBuffer: 1 << 3, // 8
+	RenderSlot: 1 << 4, // 16
 } as const;
 
 type ScopeFlagValues = (typeof ScopeFlags)[keyof typeof ScopeFlags];
diff --git a/packages/integrations/mdx/test/css-head-mdx.test.js b/packages/integrations/mdx/test/css-head-mdx.test.js
index f75892f7baba..15c15ca55821 100644
--- a/packages/integrations/mdx/test/css-head-mdx.test.js
+++ b/packages/integrations/mdx/test/css-head-mdx.test.js
@@ -49,5 +49,13 @@ describe('Head injection w/ MDX', () => {
 			const scripts = document.querySelectorAll('head script[type=module]');
 			expect(scripts).to.have.a.lengthOf(1);
 		});
+
+		it('Using component using slots.render() API', async () => {
+			const html = await fixture.readFile('/remote/index.html');
+			const { document } = parseHTML(html);
+
+			const links = document.querySelectorAll('head link[rel=stylesheet]');
+			expect(links).to.have.a.lengthOf(1);
+		});
 	});
 });
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/package.json b/packages/integrations/mdx/test/fixtures/css-head-mdx/package.json
new file mode 100644
index 000000000000..3c3c1e5a572d
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "@test/mdx-css-head-mdx",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "astro": "workspace:*",
+    "@astrojs/mdx": "workspace:*",
+    "astro-remote": "0.2.3"
+  }
+}
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/P.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/P.astro
new file mode 100644
index 000000000000..071e08a12d42
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/P.astro
@@ -0,0 +1,3 @@
+<p>
+  <slot />
+</p>
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro
index defbad800219..1804388b0524 100644
--- a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/components/UsingMdx.astro
@@ -3,8 +3,6 @@ import { getEntryBySlug } from 'astro:content';
 
 const launchWeek = await getEntryBySlug('blog', 'using-mdx');
 const { Content } = await launchWeek.render();
-
-debugger;
 ---
 
 <Content />
diff --git a/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/remote.astro b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/remote.astro
new file mode 100644
index 000000000000..9a7b76a10283
--- /dev/null
+++ b/packages/integrations/mdx/test/fixtures/css-head-mdx/src/pages/remote.astro
@@ -0,0 +1,17 @@
+---
+import '../styles/global.css'
+import Layout from '../layouts/One.astro';
+import Paragraph from '../components/P.astro';
+import { Markdown } from 'astro-remote'
+---
+
+<Layout title="Welcome to Astro.">
+	<main>
+		<Markdown
+      components={{
+				p: Paragraph,
+      }}>
+			**Removing p component fixes the problem**
+			</Markdown>
+	</main>
+</Layout>
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8a83bba42ce7..8ffbfc99b3fb 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2918,6 +2918,16 @@ importers:
       remark-toc: 8.0.1
       vite: 4.1.1
 
+  packages/integrations/mdx/test/fixtures/css-head-mdx:
+    specifiers:
+      '@astrojs/mdx': workspace:*
+      astro: workspace:*
+      astro-remote: 0.2.3
+    dependencies:
+      '@astrojs/mdx': link:../../..
+      astro: link:../../../../../astro
+      astro-remote: 0.2.3
+
   packages/integrations/mdx/test/fixtures/mdx-frontmatter-injection:
     specifiers:
       '@astrojs/mdx': workspace:*
@@ -7837,6 +7847,14 @@ packages:
       astro: link:packages/astro
     dev: false
 
+  /astro-remote/0.2.3:
+    resolution: {integrity: sha512-vsY736YjWhpFgx4KUxCBdK0QJmOk0W61VQwO7v6qmfGdIxZyx6N7hBNou57w2mw68hQSe5AbRs602pi05GDMHw==}
+    dependencies:
+      he: 1.2.0
+      marked: 4.2.12
+      ultrahtml: 0.1.3
+    dev: false
+
   /async-sema/3.1.1:
     resolution: {integrity: sha512-tLRNUXati5MFePdAk8dw7Qt7DpxPB60ofAgn8WRhW6a2rcimZnYBP9oxHiv0OHy+Wz7kPMG+t4LGdt31+4EmGg==}
     dev: false
@@ -11279,6 +11297,12 @@ packages:
     resolution: {integrity: sha512-Z1NL3Tb1M9wH4XESsCDEksWoKTdlUafKc4pt0GRwjUyXaCFZ+dc3g2erqB6zm3szA2IUSi7VnPI+o/9jnxh9hw==}
     dev: false
 
+  /marked/4.2.12:
+    resolution: {integrity: sha512-yr8hSKa3Fv4D3jdZmtMMPghgVt6TWbk86WQaWhDloQjRSQhMMYCAro7jP7VDJrjjdV8pxVxMssXS8B8Y5DZ5aw==}
+    engines: {node: '>= 12'}
+    hasBin: true
+    dev: false
+
   /matcher/3.0.0:
     resolution: {integrity: sha512-OkeDaAZ/bQCxeFAozM55PKcKU0yJMPGifLwV4Qgjitu+5MoAfSQN4lsLJeXZ1b8w0x+/Emda6MZgXS1jvsapng==}
     engines: {node: '>=10'}
@@ -14735,6 +14759,10 @@ packages:
     resolution: {integrity: sha512-o0QVGuFg24FK765Qdd5kk0zU/U4dEsCtN/GSiwNI9i8xsSVtjIAOdTaVhLwZ1nrbWxFVMxNDDl+9fednsOMsBw==}
     dev: true
 
+  /ultrahtml/0.1.3:
+    resolution: {integrity: sha512-P24ulZdT9UKyQuKA1IApdAZ+F9lwruGvmKb4pG3+sMvR3CjN0pjawPnxuSABHQFB+XqnB35TVXzJPOBYjCv6Kw==}
+    dev: false
+
   /unbox-primitive/1.0.2:
     resolution: {integrity: sha512-61pPlCD9h51VoreyJ0BReideM3MDKMKnh6+V9L08331ipq6Q8OFXZYiqP6n/tbHx4s5I9uRhcye6BrbkizkBDw==}
     dependencies:

From 50911a69427be53fdd8e6093a4213e0800dfe0d8 Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 15:02:41 -0500
Subject: [PATCH 04/11] Generate propagation map during the build

---
 packages/astro/src/core/app/index.ts          |  1 +
 packages/astro/src/core/app/types.ts          |  2 +
 packages/astro/src/core/build/generate.ts     |  1 +
 packages/astro/src/core/build/internal.ts     |  3 ++
 .../astro/src/core/build/plugins/index.ts     |  2 +
 .../src/core/build/plugins/plugin-ssr.ts      |  1 +
 .../astro/src/runtime/server/render/head.ts   |  7 +--
 .../src/vite-plugin-head-propagation/index.ts | 53 ++++++++++++++++++-
 .../mdx/test/css-head-mdx.test.js             |  5 +-
 9 files changed, 68 insertions(+), 7 deletions(-)

diff --git a/packages/astro/src/core/app/index.ts b/packages/astro/src/core/app/index.ts
index 529a450f9531..615be50aa585 100644
--- a/packages/astro/src/core/app/index.ts
+++ b/packages/astro/src/core/app/index.ts
@@ -193,6 +193,7 @@ export class App {
 				request,
 				origin: url.origin,
 				pathname,
+				propagation: this.#manifest.propagation,
 				scripts,
 				links,
 				route: routeData,
diff --git a/packages/astro/src/core/app/types.ts b/packages/astro/src/core/app/types.ts
index 587c924b92de..1d30f3e385e1 100644
--- a/packages/astro/src/core/app/types.ts
+++ b/packages/astro/src/core/app/types.ts
@@ -4,6 +4,7 @@ import type {
 	RouteData,
 	SerializedRouteData,
 	SSRLoadedRenderer,
+	SSRResult,
 } from '../../@types/astro';
 
 export type ComponentPath = string;
@@ -34,6 +35,7 @@ export interface SSRManifest {
 	renderers: SSRLoadedRenderer[];
 	entryModules: Record<string, string>;
 	assets: Set<string>;
+	propagation: SSRResult['propagation'];
 }
 
 export type SerializedSSRManifest = Omit<SSRManifest, 'routes' | 'assets'> & {
diff --git a/packages/astro/src/core/build/generate.ts b/packages/astro/src/core/build/generate.ts
index 1a708aab3765..f5f72dc5ab93 100644
--- a/packages/astro/src/core/build/generate.ts
+++ b/packages/astro/src/core/build/generate.ts
@@ -376,6 +376,7 @@ async function generatePath(
 		origin,
 		pathname,
 		request: createRequest({ url, headers: new Headers(), logging, ssr }),
+		propagation: internals.propagation,
 		scripts,
 		links,
 		route: pageData.route,
diff --git a/packages/astro/src/core/build/internal.ts b/packages/astro/src/core/build/internal.ts
index dc660f4949e0..87c817ad4bca 100644
--- a/packages/astro/src/core/build/internal.ts
+++ b/packages/astro/src/core/build/internal.ts
@@ -4,6 +4,7 @@ import type { PageBuildData, ViteID } from './types';
 import { PageOptions } from '../../vite-plugin-astro/types';
 import { prependForwardSlash, removeFileExtension } from '../path.js';
 import { viteID } from '../util.js';
+import { SSRResult } from '../../@types/astro';
 
 export interface BuildInternals {
 	/**
@@ -66,6 +67,7 @@ export interface BuildInternals {
 	staticFiles: Set<string>;
 	// The SSR entry chunk. Kept in internals to share between ssr/client build steps
 	ssrEntryChunk?: OutputChunk;
+	propagation: SSRResult['propagation'];
 }
 
 /**
@@ -95,6 +97,7 @@ export function createBuildInternals(): BuildInternals {
 		discoveredClientOnlyComponents: new Set(),
 		discoveredScripts: new Set(),
 		staticFiles: new Set(),
+		propagation: new Map(),
 	};
 }
 
diff --git a/packages/astro/src/core/build/plugins/index.ts b/packages/astro/src/core/build/plugins/index.ts
index cf0f9bf7c66d..9aa3e20b5801 100644
--- a/packages/astro/src/core/build/plugins/index.ts
+++ b/packages/astro/src/core/build/plugins/index.ts
@@ -8,6 +8,7 @@ import { pluginInternals } from './plugin-internals.js';
 import { pluginPages } from './plugin-pages.js';
 import { pluginPrerender } from './plugin-prerender.js';
 import { pluginSSR } from './plugin-ssr.js';
+import { astroHeadPropagationBuildPlugin } from '../../../vite-plugin-head-propagation/index.js';
 
 export function registerAllPlugins({ internals, options, register }: AstroBuildPluginContainer) {
 	register(pluginAliasResolve(internals));
@@ -15,6 +16,7 @@ export function registerAllPlugins({ internals, options, register }: AstroBuildP
 	register(pluginInternals(internals));
 	register(pluginPages(options, internals));
 	register(pluginCSS(options, internals));
+	register(astroHeadPropagationBuildPlugin(options, internals));
 	register(pluginPrerender(options, internals));
 	register(astroConfigBuildPlugin(options, internals));
 	register(pluginHoistedScripts(options, internals));
diff --git a/packages/astro/src/core/build/plugins/plugin-ssr.ts b/packages/astro/src/core/build/plugins/plugin-ssr.ts
index cfc58d71b345..7e62d5e3d7a8 100644
--- a/packages/astro/src/core/build/plugins/plugin-ssr.ts
+++ b/packages/astro/src/core/build/plugins/plugin-ssr.ts
@@ -211,6 +211,7 @@ function buildManifest(
 			contentDir: getContentPaths(settings.config).contentDir,
 		},
 		pageMap: null as any,
+		propagation: internals.propagation,
 		renderers: [],
 		entryModules,
 		assets: staticFiles.map((s) => settings.config.base + s),
diff --git a/packages/astro/src/runtime/server/render/head.ts b/packages/astro/src/runtime/server/render/head.ts
index ca4c17de362d..e17e9b456116 100644
--- a/packages/astro/src/runtime/server/render/head.ts
+++ b/packages/astro/src/runtime/server/render/head.ts
@@ -57,12 +57,13 @@ export function* maybeRenderHead(result: SSRResult) {
 	// as the Astro component will be the one to render the head.
 	switch (result.scope) {
 		case ScopeFlags.JSX | ScopeFlags.Slot | ScopeFlags.Astro:
-		// TODO Explain
-		case ScopeFlags.JSX | ScopeFlags.Astro | ScopeFlags.HeadBuffer: {
+		case ScopeFlags.JSX | ScopeFlags.Astro | ScopeFlags.HeadBuffer:
+		case ScopeFlags.JSX |  ScopeFlags.Slot | ScopeFlags.Astro | ScopeFlags.HeadBuffer: {
 			return;
 		}
 		case ScopeFlags.RenderSlot | ScopeFlags.Astro:
-		case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX: {
+		case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX:
+		case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX | ScopeFlags.HeadBuffer: {
 			return;
 		}
 	}
diff --git a/packages/astro/src/vite-plugin-head-propagation/index.ts b/packages/astro/src/vite-plugin-head-propagation/index.ts
index ae8075e97e4f..eedefafd9ae9 100644
--- a/packages/astro/src/vite-plugin-head-propagation/index.ts
+++ b/packages/astro/src/vite-plugin-head-propagation/index.ts
@@ -1,8 +1,12 @@
 import type { ModuleInfo } from 'rollup';
-import type { AstroSettings } from '../@types/astro';
+import type { AstroSettings, SSRResult } from '../@types/astro';
+import type { BuildInternals } from '../core/build/internal.js';
+import type { AstroBuildPlugin } from '../core/build/plugin.js';
+import type { StaticBuildOptions } from '../core/build/types';
 
 import * as vite from 'vite';
 import { getAstroMetadata } from '../vite-plugin-astro/index.js';
+import { walkParentInfos } from '../core/build/graph.js';
 
 const injectExp = /^\/\/\s*astro-head-inject/;
 /**
@@ -59,3 +63,50 @@ export default function configHeadPropagationVitePlugin({
 		},
 	};
 }
+
+export function astroHeadPropagationBuildPlugin(
+	options: StaticBuildOptions,
+	internals: BuildInternals
+): AstroBuildPlugin {
+	return {
+		build: 'ssr',
+		hooks: {
+			'build:before'() {
+				const map: SSRResult['propagation'] = new Map();
+				return {
+					vitePlugin: {
+						name: 'vite-plugin-head-propagation-build',
+						generateBundle(_opts, bundle) {
+							const appendPropagation = (info: ModuleInfo) => {
+								const astroMetadata = getAstroMetadata(info);
+								if(astroMetadata) {
+									astroMetadata.propagation = 'in-tree';
+									map.set(info.id, 'in-tree');
+								}
+							};
+
+							for(const [bundleId, output] of Object.entries(bundle)) {
+								if(output.type !== 'chunk') continue;
+								for(const [id, mod] of Object.entries(output.modules)) {
+									if (mod.code && injectExp.test(mod.code)) { 
+										for(const [info] of walkParentInfos(id, this)) {
+											appendPropagation(info);
+										}
+									}
+
+									const info = this.getModuleInfo(id);
+									if(info) {
+										appendPropagation(info);
+									}
+								}
+							}
+
+							// Save the map to internals so it can be passed into SSR and generation
+							internals.propagation = map;
+						}
+					}
+				}
+			}
+		}
+	}
+}
diff --git a/packages/integrations/mdx/test/css-head-mdx.test.js b/packages/integrations/mdx/test/css-head-mdx.test.js
index 15c15ca55821..c38f23701d34 100644
--- a/packages/integrations/mdx/test/css-head-mdx.test.js
+++ b/packages/integrations/mdx/test/css-head-mdx.test.js
@@ -38,16 +38,15 @@ describe('Head injection w/ MDX', () => {
 			expect(links).to.have.a.lengthOf(1);
 		});
 
-		it.skip('injects content from a component using Content#render()', async () => {
+		it('injects content from a component using Content#render()', async () => {
 			const html = await fixture.readFile('/DirectContentUsage/index.html');
-			console.log(html);
 			const { document } = parseHTML(html);
 
 			const links = document.querySelectorAll('head link[rel=stylesheet]');
 			expect(links).to.have.a.lengthOf(1);
 
 			const scripts = document.querySelectorAll('head script[type=module]');
-			expect(scripts).to.have.a.lengthOf(1);
+			expect(scripts).to.have.a.lengthOf(2);
 		});
 
 		it('Using component using slots.render() API', async () => {

From bf3f2c7e997c8b9721b68cb87eebf4b506a1b4aa Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 15:28:38 -0500
Subject: [PATCH 05/11] Move to a maybeHead instruction

---
 packages/astro/package.json                   |  2 +-
 packages/astro/src/core/render/result.ts      | 14 ++++++------
 .../runtime/server/render/astro/instance.ts   |  8 +++----
 .../astro/src/runtime/server/render/common.ts | 22 +++++++++++++++++++
 .../astro/src/runtime/server/render/head.ts   | 17 +-------------
 .../astro/src/runtime/server/render/types.ts  |  8 ++++++-
 pnpm-lock.yaml                                | 12 +++++-----
 7 files changed, 48 insertions(+), 35 deletions(-)

diff --git a/packages/astro/package.json b/packages/astro/package.json
index 9b189a73bd86..26e028e056f8 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -99,7 +99,7 @@
     "test:e2e:match": "playwright test -g"
   },
   "dependencies": {
-    "@astrojs/compiler": "^1.0.1",
+    "@astrojs/compiler": "next--slot-pass",
     "@astrojs/language-server": "^0.28.3",
     "@astrojs/markdown-remark": "^2.0.1",
     "@astrojs/telemetry": "^2.0.0",
diff --git a/packages/astro/src/core/render/result.ts b/packages/astro/src/core/render/result.ts
index ea360d8baff9..8f0da82749ac 100644
--- a/packages/astro/src/core/render/result.ts
+++ b/packages/astro/src/core/render/result.ts
@@ -9,7 +9,7 @@ import type {
 	SSRLoadedRenderer,
 	SSRResult,
 } from '../../@types/astro';
-import { addScopeFlag, renderSlot, stringifyChunk, ScopeFlags } from '../../runtime/server/index.js';
+import { addScopeFlag, renderSlot, stringifyChunk, ScopeFlags, createScopedResult } from '../../runtime/server/index.js';
 import { renderJSX } from '../../runtime/server/jsx.js';
 import { AstroCookies } from '../cookies/index.js';
 import { AstroError, AstroErrorData } from '../errors/index.js';
@@ -89,7 +89,7 @@ class Slots {
 	public async render(name: string, args: any[] = []) {
 		if (!this.#slots || !this.has(name)) return;
 
-		addScopeFlag(this.#result, ScopeFlags.RenderSlot);
+		const scoped = createScopedResult(this.#result, ScopeFlags.RenderSlot);
 		if (!Array.isArray(args)) {
 			warn(
 				this.#loggingOpts,
@@ -98,26 +98,26 @@ class Slots {
 			);
 		} else if (args.length > 0) {
 			const slotValue = this.#slots[name];
-			const component = typeof slotValue === 'function' ? await slotValue() : await slotValue;
+			const component = typeof slotValue === 'function' ? await slotValue(scoped) : await slotValue;
 
 			// Astro
 			const expression = getFunctionExpression(component);
 			if (expression) {
 				const slot = expression(...args);
-				return await renderSlot(this.#result, slot).then((res) =>
+				return await renderSlot(scoped, slot).then((res) =>
 					res != null ? String(res) : res
 				);
 			}
 			// JSX
 			if (typeof component === 'function') {
-				return await renderJSX(this.#result, component(...args)).then((res) =>
+				return await renderJSX(scoped, component(...args)).then((res) =>
 					res != null ? String(res) : res
 				);
 			}
 		}
 
-		const content = await renderSlot(this.#result, this.#slots[name]);
-		const outHTML = stringifyChunk(this.#result, content);
+		const content = await renderSlot(scoped, this.#slots[name]);
+		const outHTML = stringifyChunk(scoped, content);
 
 		return outHTML;
 	}
diff --git a/packages/astro/src/runtime/server/render/astro/instance.ts b/packages/astro/src/runtime/server/render/astro/instance.ts
index c330b1319f90..d99a26364339 100644
--- a/packages/astro/src/runtime/server/render/astro/instance.ts
+++ b/packages/astro/src/runtime/server/render/astro/instance.ts
@@ -7,10 +7,10 @@ import { isPromise } from '../../util.js';
 import { renderChild } from '../any.js';
 import { isAPropagatingComponent } from './factory.js';
 import { isHeadAndContent } from './head-and-content.js';
-import { addScopeFlag, removeScopeFlag, ScopeFlags } from '../scope.js';
+import { createScopedResult, ScopeFlags } from '../scope.js';
 
 type ComponentProps = Record<string | number, any>;
-type ComponentSlotValue = () => ReturnType<typeof renderTemplate>;
+type ComponentSlotValue = (result: SSRResult) => ReturnType<typeof renderTemplate>;
 export type ComponentSlots = Record<string, ComponentSlotValue>;
 export type ComponentSlotsWithValues = Record<string, ReturnType<ComponentSlotValue>>;
 
@@ -34,9 +34,9 @@ export class AstroComponentInstance {
 		this.props = props;
 		this.factory = factory;
 		this.slotValues = {};
-		addScopeFlag(result, ScopeFlags.Slot);
+		const scoped = createScopedResult(result, ScopeFlags.Slot);
 		for (const name in slots) {
-			this.slotValues[name] = slots[name]();
+			this.slotValues[name] = slots[name](scoped);
 		}
 	}
 
diff --git a/packages/astro/src/runtime/server/render/common.ts b/packages/astro/src/runtime/server/render/common.ts
index def7dedd37e0..44946ef41174 100644
--- a/packages/astro/src/runtime/server/render/common.ts
+++ b/packages/astro/src/runtime/server/render/common.ts
@@ -10,6 +10,7 @@ import {
 } from '../scripts.js';
 import { renderAllHeadContent } from './head.js';
 import { isSlotString, type SlotString } from './slot.js';
+import { ScopeFlags } from './scope.js';
 
 export const Fragment = Symbol.for('astro:fragment');
 export const Renderer = Symbol.for('astro:renderer');
@@ -48,6 +49,27 @@ export function stringifyChunk(result: SSRResult, chunk: string | SlotString | R
 				}
 				return renderAllHeadContent(result);
 			}
+			case 'maybe-head': {
+				const scope = instruction.scope;
+				switch (scope) {
+					// JSX with an Astro slot
+					case ScopeFlags.JSX | ScopeFlags.Astro:
+					case ScopeFlags.JSX | ScopeFlags.Slot | ScopeFlags.Astro:
+					case ScopeFlags.JSX | ScopeFlags.Astro | ScopeFlags.HeadBuffer:
+					case ScopeFlags.JSX |  ScopeFlags.Slot | ScopeFlags.Astro | ScopeFlags.HeadBuffer: {
+						return '';
+					}
+
+					// Astro.slots.render('default') should never render head content.
+					case ScopeFlags.RenderSlot | ScopeFlags.Astro:
+					case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX:
+					case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX | ScopeFlags.HeadBuffer: {
+						return '';
+					}
+				}
+
+				return renderAllHeadContent(result);
+			}
 		}
 	} else {
 		if (isSlotString(chunk as string)) {
diff --git a/packages/astro/src/runtime/server/render/head.ts b/packages/astro/src/runtime/server/render/head.ts
index e17e9b456116..4bd072ee7918 100644
--- a/packages/astro/src/runtime/server/render/head.ts
+++ b/packages/astro/src/runtime/server/render/head.ts
@@ -53,22 +53,7 @@ export function* maybeRenderHead(result: SSRResult) {
 		return;
 	}
 
-	// Don't render the head inside of a JSX component that's inside of an Astro component
-	// as the Astro component will be the one to render the head.
-	switch (result.scope) {
-		case ScopeFlags.JSX | ScopeFlags.Slot | ScopeFlags.Astro:
-		case ScopeFlags.JSX | ScopeFlags.Astro | ScopeFlags.HeadBuffer:
-		case ScopeFlags.JSX |  ScopeFlags.Slot | ScopeFlags.Astro | ScopeFlags.HeadBuffer: {
-			return;
-		}
-		case ScopeFlags.RenderSlot | ScopeFlags.Astro:
-		case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX:
-		case ScopeFlags.RenderSlot | ScopeFlags.Astro | ScopeFlags.JSX | ScopeFlags.HeadBuffer: {
-			return;
-		}
-	}
-
 	// This is an instruction informing the page rendering that head might need rendering.
 	// This allows the page to deduplicate head injections.
-	yield { type: 'head', result } as const;
+	yield { type: 'maybe-head', result, scope: result.scope } as const;
 }
diff --git a/packages/astro/src/runtime/server/render/types.ts b/packages/astro/src/runtime/server/render/types.ts
index 3aa3a16e3cef..a16ec034b32d 100644
--- a/packages/astro/src/runtime/server/render/types.ts
+++ b/packages/astro/src/runtime/server/render/types.ts
@@ -12,4 +12,10 @@ export type RenderHeadInstruction = {
 	result: SSRResult;
 };
 
-export type RenderInstruction = RenderDirectiveInstruction | RenderHeadInstruction;
+export type MaybeRenderHeadInstruction = {
+	type: 'maybe-head';
+	result: SSRResult;
+	scope: number;
+}
+
+export type RenderInstruction = RenderDirectiveInstruction | RenderHeadInstruction | MaybeRenderHeadInstruction;
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8ffbfc99b3fb..bb4b28669089 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -375,7 +375,7 @@ importers:
 
   packages/astro:
     specifiers:
-      '@astrojs/compiler': ^1.0.1
+      '@astrojs/compiler': next--slot-pass
       '@astrojs/language-server': ^0.28.3
       '@astrojs/markdown-remark': ^2.0.1
       '@astrojs/telemetry': ^2.0.0
@@ -465,7 +465,7 @@ importers:
       yargs-parser: ^21.0.1
       zod: ^3.17.3
     dependencies:
-      '@astrojs/compiler': 1.0.1
+      '@astrojs/compiler': 0.0.0-slot-pass-20230206200849
       '@astrojs/language-server': 0.28.3
       '@astrojs/markdown-remark': link:../markdown/remark
       '@astrojs/telemetry': link:../telemetry
@@ -3864,13 +3864,13 @@ packages:
       sisteransi: 1.0.5
     dev: false
 
+  /@astrojs/compiler/0.0.0-slot-pass-20230206200849:
+    resolution: {integrity: sha512-1jl/e96lIO6+5GNDUb49bwAOh170uk7/VJ2PQTdBOw0Xwo0sK/JA8xC0z/ySsEuQ/5nJ8Lo7yZW1KPro9qIbPw==}
+    dev: false
+
   /@astrojs/compiler/0.31.4:
     resolution: {integrity: sha512-6bBFeDTtPOn4jZaiD3p0f05MEGQL9pw2Zbfj546oFETNmjJFWO3nzHz6/m+P53calknCvyVzZ5YhoBLIvzn5iw==}
 
-  /@astrojs/compiler/1.0.1:
-    resolution: {integrity: sha512-77aacobLKcL98NmhK3OBS5EHIrX9gs1ckB/vGSIdkVZuB7u51V4jh05I6W0tSvG7/86tALv6QtHTRZ8rLhFTbQ==}
-    dev: false
-
   /@astrojs/language-server/0.28.3:
     resolution: {integrity: sha512-fPovAX/X46eE2w03jNRMpQ7W9m2mAvNt4Ay65lD9wl1Z5vIQYxlg7Enp9qP225muTr4jSVB5QiLumFJmZMAaVA==}
     hasBin: true

From 1181f3e200bd756ae6d9e1fff16eefd892e3311d Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 15:43:17 -0500
Subject: [PATCH 06/11] Properly serialize for SSR

---
 packages/astro/src/core/app/common.ts               | 2 ++
 packages/astro/src/core/app/types.ts                | 4 +++-
 packages/astro/src/core/build/plugins/plugin-ssr.ts | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/packages/astro/src/core/app/common.ts b/packages/astro/src/core/app/common.ts
index 2da98f1c6022..4b14321762af 100644
--- a/packages/astro/src/core/app/common.ts
+++ b/packages/astro/src/core/app/common.ts
@@ -14,10 +14,12 @@ export function deserializeManifest(serializedManifest: SerializedSSRManifest):
 	}
 
 	const assets = new Set<string>(serializedManifest.assets);
+	const propagation = new Map(serializedManifest.propagation);
 
 	return {
 		...serializedManifest,
 		assets,
+		propagation,
 		routes,
 	};
 }
diff --git a/packages/astro/src/core/app/types.ts b/packages/astro/src/core/app/types.ts
index 1d30f3e385e1..cf85d0387bce 100644
--- a/packages/astro/src/core/app/types.ts
+++ b/packages/astro/src/core/app/types.ts
@@ -1,6 +1,7 @@
 import type { MarkdownRenderingOptions } from '@astrojs/markdown-remark';
 import type {
 	ComponentInstance,
+	PropagationHint,
 	RouteData,
 	SerializedRouteData,
 	SSRLoadedRenderer,
@@ -38,9 +39,10 @@ export interface SSRManifest {
 	propagation: SSRResult['propagation'];
 }
 
-export type SerializedSSRManifest = Omit<SSRManifest, 'routes' | 'assets'> & {
+export type SerializedSSRManifest = Omit<SSRManifest, 'routes' | 'assets' | 'propagation'> & {
 	routes: SerializedRouteInfo[];
 	assets: string[];
+	propagation: readonly [string, PropagationHint][];
 };
 
 export type AdapterCreateExports<T = any> = (
diff --git a/packages/astro/src/core/build/plugins/plugin-ssr.ts b/packages/astro/src/core/build/plugins/plugin-ssr.ts
index 7e62d5e3d7a8..d4536b92c8ab 100644
--- a/packages/astro/src/core/build/plugins/plugin-ssr.ts
+++ b/packages/astro/src/core/build/plugins/plugin-ssr.ts
@@ -211,7 +211,7 @@ function buildManifest(
 			contentDir: getContentPaths(settings.config).contentDir,
 		},
 		pageMap: null as any,
-		propagation: internals.propagation,
+		propagation: Array.from(internals.propagation),
 		renderers: [],
 		entryModules,
 		assets: staticFiles.map((s) => settings.config.base + s),

From 56a7c040204d15b85074cce844d926786fd76dbc Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 15:46:10 -0500
Subject: [PATCH 07/11] More conservative scoping

---
 packages/astro/src/runtime/server/render/astro/instance.ts | 6 +++---
 packages/astro/src/runtime/server/render/common.ts         | 1 -
 packages/astro/src/runtime/server/render/page.ts           | 7 +++----
 3 files changed, 6 insertions(+), 8 deletions(-)

diff --git a/packages/astro/src/runtime/server/render/astro/instance.ts b/packages/astro/src/runtime/server/render/astro/instance.ts
index d99a26364339..45fdd6d50a02 100644
--- a/packages/astro/src/runtime/server/render/astro/instance.ts
+++ b/packages/astro/src/runtime/server/render/astro/instance.ts
@@ -40,14 +40,14 @@ export class AstroComponentInstance {
 		}
 	}
 
-	async init() {
-		this.returnValue = this.factory(this.result, this.props, this.slotValues);
+	async init(result: SSRResult) {
+		this.returnValue = this.factory(result, this.props, this.slotValues);
 		return this.returnValue;
 	}
 
 	async *render() {
 		if (this.returnValue === undefined) {
-			await this.init();
+			await this.init(this.result);
 		}
 
 		let value: AstroFactoryReturnValue | undefined = this.returnValue;
diff --git a/packages/astro/src/runtime/server/render/common.ts b/packages/astro/src/runtime/server/render/common.ts
index 44946ef41174..604844b01b09 100644
--- a/packages/astro/src/runtime/server/render/common.ts
+++ b/packages/astro/src/runtime/server/render/common.ts
@@ -53,7 +53,6 @@ export function stringifyChunk(result: SSRResult, chunk: string | SlotString | R
 				const scope = instruction.scope;
 				switch (scope) {
 					// JSX with an Astro slot
-					case ScopeFlags.JSX | ScopeFlags.Astro:
 					case ScopeFlags.JSX | ScopeFlags.Slot | ScopeFlags.Astro:
 					case ScopeFlags.JSX | ScopeFlags.Astro | ScopeFlags.HeadBuffer:
 					case ScopeFlags.JSX |  ScopeFlags.Slot | ScopeFlags.Astro | ScopeFlags.HeadBuffer: {
diff --git a/packages/astro/src/runtime/server/render/page.ts b/packages/astro/src/runtime/server/render/page.ts
index 8ae2969f5841..a9c1af77bb9c 100644
--- a/packages/astro/src/runtime/server/render/page.ts
+++ b/packages/astro/src/runtime/server/render/page.ts
@@ -15,7 +15,7 @@ import {
 import { chunkToByteArray, encoder, HTMLParts } from './common.js';
 import { renderComponent } from './component.js';
 import { maybeRenderHead } from './head.js';
-import { addScopeFlag, removeScopeFlag, ScopeFlags } from './scope.js';
+import { addScopeFlag, createScopedResult, removeScopeFlag, ScopeFlags } from './scope.js';
 
 const needsHeadRenderingSymbol = Symbol.for('astro.needsHeadRendering');
 
@@ -56,18 +56,17 @@ async function iterableToHTMLBytes(
 // to be propagated up.
 async function bufferHeadContent(result: SSRResult) {
 	const iterator = result.propagators.values();
-	addScopeFlag(result, ScopeFlags.HeadBuffer);
+	const scoped = createScopedResult(result, ScopeFlags.HeadBuffer);
 	while (true) {
 		const { value, done } = iterator.next();
 		if (done) {
 			break;
 		}
-		const returnValue = await value.init();
+		const returnValue = await value.init(scoped);
 		if (isHeadAndContent(returnValue)) {
 			result.extraHead.push(returnValue.head);
 		}
 	}
-	removeScopeFlag(result, ScopeFlags.HeadBuffer);
 }
 
 export async function renderPage(

From 6e8169dd69812c4b43de1e65647c793ab2bd89cc Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 16:08:11 -0500
Subject: [PATCH 08/11] Maybe had should honor result._metadata.hasRenderedHead

---
 packages/astro/src/runtime/server/render/common.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/packages/astro/src/runtime/server/render/common.ts b/packages/astro/src/runtime/server/render/common.ts
index 604844b01b09..5283eaa12b14 100644
--- a/packages/astro/src/runtime/server/render/common.ts
+++ b/packages/astro/src/runtime/server/render/common.ts
@@ -50,6 +50,10 @@ export function stringifyChunk(result: SSRResult, chunk: string | SlotString | R
 				return renderAllHeadContent(result);
 			}
 			case 'maybe-head': {
+				if (result._metadata.hasRenderedHead) {
+					return '';
+				}
+
 				const scope = instruction.scope;
 				switch (scope) {
 					// JSX with an Astro slot

From c44c8bf7e0b792c8fd7f13a17ce7b2a28abda46b Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 16:37:56 -0500
Subject: [PATCH 09/11] Properly type slots

---
 packages/astro/src/core/render/result.ts      |  8 +++---
 packages/astro/src/runtime/server/index.ts    |  3 +--
 .../src/runtime/server/render/astro/index.ts  |  2 +-
 .../runtime/server/render/astro/instance.ts   | 10 +++----
 .../src/runtime/server/render/component.ts    |  4 +--
 .../astro/src/runtime/server/render/index.ts  |  4 +--
 .../astro/src/runtime/server/render/slot.ts   | 27 +++++++++++--------
 7 files changed, 29 insertions(+), 29 deletions(-)

diff --git a/packages/astro/src/core/render/result.ts b/packages/astro/src/core/render/result.ts
index 8f0da82749ac..5aa42b258a95 100644
--- a/packages/astro/src/core/render/result.ts
+++ b/packages/astro/src/core/render/result.ts
@@ -9,7 +9,7 @@ import type {
 	SSRLoadedRenderer,
 	SSRResult,
 } from '../../@types/astro';
-import { addScopeFlag, renderSlot, stringifyChunk, ScopeFlags, createScopedResult } from '../../runtime/server/index.js';
+import { renderSlot, stringifyChunk, ScopeFlags, createScopedResult, ComponentSlots } from '../../runtime/server/index.js';
 import { renderJSX } from '../../runtime/server/jsx.js';
 import { AstroCookies } from '../cookies/index.js';
 import { AstroError, AstroErrorData } from '../errors/index.js';
@@ -55,10 +55,10 @@ function getFunctionExpression(slot: any) {
 
 class Slots {
 	#result: SSRResult;
-	#slots: Record<string, any> | null;
+	#slots: ComponentSlots | null;
 	#loggingOpts: LogOptions;
 
-	constructor(result: SSRResult, slots: Record<string, any> | null, logging: LogOptions) {
+	constructor(result: SSRResult, slots: ComponentSlots | null, logging: LogOptions) {
 		this.#result = result;
 		this.#slots = slots;
 		this.#loggingOpts = logging;
@@ -110,7 +110,7 @@ class Slots {
 			}
 			// JSX
 			if (typeof component === 'function') {
-				return await renderJSX(scoped, component(...args)).then((res) =>
+				return await renderJSX(scoped, (component as any)(...args)).then((res) =>
 					res != null ? String(res) : res
 				);
 			}
diff --git a/packages/astro/src/runtime/server/index.ts b/packages/astro/src/runtime/server/index.ts
index ba5c32d22c5a..aa9da8696b00 100644
--- a/packages/astro/src/runtime/server/index.ts
+++ b/packages/astro/src/runtime/server/index.ts
@@ -33,9 +33,8 @@ export {
 export type {
 	AstroComponentFactory,
 	AstroComponentInstance,
-	AstroComponentSlots,
-	AstroComponentSlotsWithValues,
 	RenderInstruction,
+	ComponentSlots
 } from './render/index.js';
 
 import { markHTMLString } from './escape.js';
diff --git a/packages/astro/src/runtime/server/render/astro/index.ts b/packages/astro/src/runtime/server/render/astro/index.ts
index 03d97b14875c..cbddf7876e8e 100644
--- a/packages/astro/src/runtime/server/render/astro/index.ts
+++ b/packages/astro/src/runtime/server/render/astro/index.ts
@@ -1,7 +1,7 @@
 export type { AstroComponentFactory } from './factory';
 export { isAstroComponentFactory, renderToString } from './factory.js';
 export { createHeadAndContent, isHeadAndContent } from './head-and-content.js';
-export type { AstroComponentInstance, ComponentSlots, ComponentSlotsWithValues } from './instance';
+export type { AstroComponentInstance } from './instance';
 export { createAstroComponentInstance, isAstroComponentInstance } from './instance.js';
 export {
 	isRenderTemplateResult,
diff --git a/packages/astro/src/runtime/server/render/astro/instance.ts b/packages/astro/src/runtime/server/render/astro/instance.ts
index 45fdd6d50a02..171cc1a546de 100644
--- a/packages/astro/src/runtime/server/render/astro/instance.ts
+++ b/packages/astro/src/runtime/server/render/astro/instance.ts
@@ -1,6 +1,6 @@
 import type { SSRResult } from '../../../../@types/astro';
 import type { AstroComponentFactory, AstroFactoryReturnValue } from './factory.js';
-import type { renderTemplate } from './render-template.js';
+import type { ComponentSlots } from '../slot.js';
 
 import { HydrationDirectiveProps } from '../../hydration.js';
 import { isPromise } from '../../util.js';
@@ -10,9 +10,6 @@ import { isHeadAndContent } from './head-and-content.js';
 import { createScopedResult, ScopeFlags } from '../scope.js';
 
 type ComponentProps = Record<string | number, any>;
-type ComponentSlotValue = (result: SSRResult) => ReturnType<typeof renderTemplate>;
-export type ComponentSlots = Record<string, ComponentSlotValue>;
-export type ComponentSlotsWithValues = Record<string, ReturnType<ComponentSlotValue>>;
 
 const astroComponentInstanceSym = Symbol.for('astro.componentInstance');
 
@@ -21,7 +18,7 @@ export class AstroComponentInstance {
 
 	private readonly result: SSRResult;
 	private readonly props: ComponentProps;
-	private readonly slotValues: ComponentSlotsWithValues;
+	private readonly slotValues: ComponentSlots;
 	private readonly factory: AstroComponentFactory;
 	private returnValue: ReturnType<AstroComponentFactory> | undefined;
 	constructor(
@@ -36,7 +33,8 @@ export class AstroComponentInstance {
 		this.slotValues = {};
 		const scoped = createScopedResult(result, ScopeFlags.Slot);
 		for (const name in slots) {
-			this.slotValues[name] = slots[name](scoped);
+			const value = slots[name](scoped);
+			this.slotValues[name] = () => value;
 		}
 	}
 
diff --git a/packages/astro/src/runtime/server/render/component.ts b/packages/astro/src/runtime/server/render/component.ts
index 034e796677a2..36aec94cfbae 100644
--- a/packages/astro/src/runtime/server/render/component.ts
+++ b/packages/astro/src/runtime/server/render/component.ts
@@ -17,7 +17,7 @@ import {
 } from './astro/index.js';
 import { Fragment, Renderer, stringifyChunk } from './common.js';
 import { componentIsHTMLElement, renderHTMLElement } from './dom.js';
-import { renderSlot, renderSlots } from './slot.js';
+import { ComponentSlots, renderSlot, renderSlots } from './slot.js';
 import { formatList, internalSpreadAttributes, renderElement, voidElementNames } from './util.js';
 
 const rendererAliases = new Map([['solid', 'solid-js']]);
@@ -330,7 +330,7 @@ function sanitizeElementName(tag: string) {
 	return tag.trim().split(unsafe)[0].trim();
 }
 
-async function renderFragmentComponent(result: SSRResult, slots: any = {}) {
+async function renderFragmentComponent(result: SSRResult, slots: ComponentSlots = {}) {
 	const children = await renderSlot(result, slots?.default);
 	if (children == null) {
 		return children;
diff --git a/packages/astro/src/runtime/server/render/index.ts b/packages/astro/src/runtime/server/render/index.ts
index 1686300ccb22..092feb86b258 100644
--- a/packages/astro/src/runtime/server/render/index.ts
+++ b/packages/astro/src/runtime/server/render/index.ts
@@ -1,8 +1,6 @@
 export type {
 	AstroComponentFactory,
 	AstroComponentInstance,
-	ComponentSlots as AstroComponentSlots,
-	ComponentSlotsWithValues as AstroComponentSlotsWithValues,
 } from './astro/index';
 export {
 	createHeadAndContent,
@@ -15,7 +13,7 @@ export { renderComponent, renderComponentToIterable } from './component.js';
 export { renderHTMLElement } from './dom.js';
 export { maybeRenderHead, renderHead } from './head.js';
 export { renderPage } from './page.js';
-export { renderSlot } from './slot.js';
+export { renderSlot, type ComponentSlots } from './slot.js';
 export { createScopedResult, ScopeFlags, addScopeFlag, removeScopeFlag } from './scope.js';
 export { renderScriptElement, renderStyleElement, renderUniqueStylesheet } from './tags.js';
 export type { RenderInstruction } from './types';
diff --git a/packages/astro/src/runtime/server/render/slot.ts b/packages/astro/src/runtime/server/render/slot.ts
index c119bea8f5d7..eb9762f94bcf 100644
--- a/packages/astro/src/runtime/server/render/slot.ts
+++ b/packages/astro/src/runtime/server/render/slot.ts
@@ -1,9 +1,13 @@
 import type { SSRResult } from '../../../@types/astro.js';
 import type { RenderInstruction } from './types.js';
+import type { renderTemplate } from './astro/render-template.js';
 
 import { HTMLString, markHTMLString } from '../escape.js';
 import { renderChild } from './any.js';
-import { ScopeFlags, addScopeFlag, removeScopeFlag } from './scope.js';
+import { ScopeFlags, addScopeFlag, removeScopeFlag, createScopedResult } from './scope.js';
+
+export type ComponentSlots = Record<string, ComponentSlotValue>;
+export type ComponentSlotValue = (result: SSRResult) => ReturnType<typeof renderTemplate>;
 
 const slotString = Symbol.for('astro:slot-string');
 
@@ -23,12 +27,12 @@ export function isSlotString(str: string): str is any {
 
 export async function renderSlot(
 	result: SSRResult,
-	slotted: string,
-	fallback?: any
+	slotted: ComponentSlotValue,
+	fallback?: ComponentSlotValue
 ): Promise<string> {
 	if (slotted) {
-		addScopeFlag(result, ScopeFlags.Slot);
-		let iterator = renderChild(slotted);
+		const scoped = createScopedResult(result, ScopeFlags.Slot);
+		let iterator = renderChild(slotted(scoped));
 		let content = '';
 		let instructions: null | RenderInstruction[] = null;
 		for await (const chunk of iterator) {
@@ -41,12 +45,13 @@ export async function renderSlot(
 				content += chunk;
 			}
 		}
-		// Remove the flag since we are now outside of the scope.
-		removeScopeFlag(result, ScopeFlags.Slot);
-		
 		return markHTMLString(new SlotString(content, instructions));
 	}
-	return fallback;
+
+	if(fallback) {
+		return renderSlot(result, fallback);
+	}
+	return '';
 }
 
 interface RenderSlotsResult {
@@ -54,13 +59,13 @@ interface RenderSlotsResult {
 	children: Record<string, string>;
 }
 
-export async function renderSlots(result: SSRResult, slots: any = {}): Promise<RenderSlotsResult> {
+export async function renderSlots(result: SSRResult, slots: ComponentSlots = {}): Promise<RenderSlotsResult> {
 	let slotInstructions: RenderSlotsResult['slotInstructions'] = null;
 	let children: RenderSlotsResult['children'] = {};
 	if (slots) {
 		await Promise.all(
 			Object.entries(slots).map(([key, value]) =>
-				renderSlot(result, value as string).then((output: any) => {
+				renderSlot(result, value).then((output: any) => {
 					if (output.instructions) {
 						if (slotInstructions === null) {
 							slotInstructions = [];

From 8b3afc5269b6cd391e843f9da1dcfdde2d955d89 Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 16:53:41 -0500
Subject: [PATCH 10/11] Allow template result to be passed

---
 packages/astro/src/core/render/result.ts         |  2 +-
 packages/astro/src/runtime/server/render/slot.ts | 11 ++++++-----
 2 files changed, 7 insertions(+), 6 deletions(-)

diff --git a/packages/astro/src/core/render/result.ts b/packages/astro/src/core/render/result.ts
index 5aa42b258a95..e236b35a4bc5 100644
--- a/packages/astro/src/core/render/result.ts
+++ b/packages/astro/src/core/render/result.ts
@@ -103,7 +103,7 @@ class Slots {
 			// Astro
 			const expression = getFunctionExpression(component);
 			if (expression) {
-				const slot = expression(...args);
+				const slot = () => expression(...args);
 				return await renderSlot(scoped, slot).then((res) =>
 					res != null ? String(res) : res
 				);
diff --git a/packages/astro/src/runtime/server/render/slot.ts b/packages/astro/src/runtime/server/render/slot.ts
index eb9762f94bcf..aac133e6ef6f 100644
--- a/packages/astro/src/runtime/server/render/slot.ts
+++ b/packages/astro/src/runtime/server/render/slot.ts
@@ -4,10 +4,11 @@ import type { renderTemplate } from './astro/render-template.js';
 
 import { HTMLString, markHTMLString } from '../escape.js';
 import { renderChild } from './any.js';
-import { ScopeFlags, addScopeFlag, removeScopeFlag, createScopedResult } from './scope.js';
+import { ScopeFlags, createScopedResult } from './scope.js';
 
+type RenderTemplateResult = ReturnType<typeof renderTemplate>;
 export type ComponentSlots = Record<string, ComponentSlotValue>;
-export type ComponentSlotValue = (result: SSRResult) => ReturnType<typeof renderTemplate>;
+export type ComponentSlotValue = (result: SSRResult) => RenderTemplateResult;
 
 const slotString = Symbol.for('astro:slot-string');
 
@@ -27,12 +28,12 @@ export function isSlotString(str: string): str is any {
 
 export async function renderSlot(
 	result: SSRResult,
-	slotted: ComponentSlotValue,
-	fallback?: ComponentSlotValue
+	slotted: ComponentSlotValue | RenderTemplateResult,
+	fallback?: ComponentSlotValue | RenderTemplateResult
 ): Promise<string> {
 	if (slotted) {
 		const scoped = createScopedResult(result, ScopeFlags.Slot);
-		let iterator = renderChild(slotted(scoped));
+		let iterator = renderChild(typeof slotted === 'function' ? slotted(scoped) : slotted);
 		let content = '';
 		let instructions: null | RenderInstruction[] = null;
 		for await (const chunk of iterator) {

From f3459001b244e778a0a19ccf75dd3a3d6dea102c Mon Sep 17 00:00:00 2001
From: Matthew Phillips <matthew@skypack.dev>
Date: Mon, 6 Feb 2023 17:10:31 -0500
Subject: [PATCH 11/11] Add changeset

---
 .changeset/pretty-bananas-own.md           | 10 ++++++++++
 packages/astro/package.json                |  2 +-
 packages/astro/src/core/compile/compile.ts |  1 +
 pnpm-lock.yaml                             | 12 ++++++------
 4 files changed, 18 insertions(+), 7 deletions(-)
 create mode 100644 .changeset/pretty-bananas-own.md

diff --git a/.changeset/pretty-bananas-own.md b/.changeset/pretty-bananas-own.md
new file mode 100644
index 000000000000..322ce96e24c8
--- /dev/null
+++ b/.changeset/pretty-bananas-own.md
@@ -0,0 +1,10 @@
+---
+'astro': patch
+---
+
+Fix MDX related head placement bugs
+
+This fixes a variety of head content placement bugs (such as page `<link>`) related to MDX, especially when used in content collections. Issues fixed:
+
+- Head content being placed in the body instead of the head.
+- Head content missing when rendering an MDX component from within a nested Astro component.
diff --git a/packages/astro/package.json b/packages/astro/package.json
index 26e028e056f8..35b83d5a9341 100644
--- a/packages/astro/package.json
+++ b/packages/astro/package.json
@@ -99,7 +99,7 @@
     "test:e2e:match": "playwright test -g"
   },
   "dependencies": {
-    "@astrojs/compiler": "next--slot-pass",
+    "@astrojs/compiler": "^1.1.0",
     "@astrojs/language-server": "^0.28.3",
     "@astrojs/markdown-remark": "^2.0.1",
     "@astrojs/telemetry": "^2.0.0",
diff --git a/packages/astro/src/core/compile/compile.ts b/packages/astro/src/core/compile/compile.ts
index 7e8dc8a31927..a0199a2fb703 100644
--- a/packages/astro/src/core/compile/compile.ts
+++ b/packages/astro/src/core/compile/compile.ts
@@ -42,6 +42,7 @@ export async function compile({
 			sourcemap: 'both',
 			internalURL: 'astro/server/index.js',
 			astroGlobalArgs: JSON.stringify(astroConfig.site),
+			resultScopedSlot: true,
 			preprocessStyle: createStylePreprocessor({
 				filename,
 				viteConfig,
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index bb4b28669089..aa398911206f 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -375,7 +375,7 @@ importers:
 
   packages/astro:
     specifiers:
-      '@astrojs/compiler': next--slot-pass
+      '@astrojs/compiler': ^1.1.0
       '@astrojs/language-server': ^0.28.3
       '@astrojs/markdown-remark': ^2.0.1
       '@astrojs/telemetry': ^2.0.0
@@ -465,7 +465,7 @@ importers:
       yargs-parser: ^21.0.1
       zod: ^3.17.3
     dependencies:
-      '@astrojs/compiler': 0.0.0-slot-pass-20230206200849
+      '@astrojs/compiler': 1.1.0
       '@astrojs/language-server': 0.28.3
       '@astrojs/markdown-remark': link:../markdown/remark
       '@astrojs/telemetry': link:../telemetry
@@ -3864,13 +3864,13 @@ packages:
       sisteransi: 1.0.5
     dev: false
 
-  /@astrojs/compiler/0.0.0-slot-pass-20230206200849:
-    resolution: {integrity: sha512-1jl/e96lIO6+5GNDUb49bwAOh170uk7/VJ2PQTdBOw0Xwo0sK/JA8xC0z/ySsEuQ/5nJ8Lo7yZW1KPro9qIbPw==}
-    dev: false
-
   /@astrojs/compiler/0.31.4:
     resolution: {integrity: sha512-6bBFeDTtPOn4jZaiD3p0f05MEGQL9pw2Zbfj546oFETNmjJFWO3nzHz6/m+P53calknCvyVzZ5YhoBLIvzn5iw==}
 
+  /@astrojs/compiler/1.1.0:
+    resolution: {integrity: sha512-C4kTwirys+HafufMqaxCbML2wqkGaXJM+5AekXh/v1IIOnMIdcEON9GBYsG6qa8aAmLhZ58aUZGPhzcA3Dx7Uw==}
+    dev: false
+
   /@astrojs/language-server/0.28.3:
     resolution: {integrity: sha512-fPovAX/X46eE2w03jNRMpQ7W9m2mAvNt4Ay65lD9wl1Z5vIQYxlg7Enp9qP225muTr4jSVB5QiLumFJmZMAaVA==}
     hasBin: true