From 7900e3eafac7a59a9d0af37069faf3e3b720918c Mon Sep 17 00:00:00 2001
From: Tan Li Hau <tanhauhau@users.noreply.github.com>
Date: Tue, 15 Sep 2020 20:32:55 +0800
Subject: [PATCH] fix style scoping with > * (#5400)

---
 CHANGELOG.md                                  |  4 ++
 src/compiler/compile/css/Selector.ts          |  4 +-
 .../_config.js                                | 45 +++++++++++++++++++
 .../expected.css                              |  1 +
 .../input.svelte                              | 23 ++++++++++
 5 files changed, 75 insertions(+), 2 deletions(-)
 create mode 100644 test/css/samples/unused-selector-child-combinator/_config.js
 create mode 100644 test/css/samples/unused-selector-child-combinator/expected.css
 create mode 100644 test/css/samples/unused-selector-child-combinator/input.svelte

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 21a9441c41..d1481dd850 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Svelte changelog
 
+## Unreleased
+
+* Fix scoping of styles involving child selector and `*` ([#5370](https://github.com/sveltejs/svelte/issues/5370))
+
 ## 3.25.0
 
 * Use `null` rather than `undefined` for coerced bound value of `<input type="number">` ([#1701](https://github.com/sveltejs/svelte/issues/1701))
diff --git a/src/compiler/compile/css/Selector.ts b/src/compiler/compile/css/Selector.ts
index 6bc046c93e..e3e1fa96bb 100644
--- a/src/compiler/compile/css/Selector.ts
+++ b/src/compiler/compile/css/Selector.ts
@@ -152,7 +152,7 @@ function apply_selector(blocks: Block[], node: Element, stack: Element[], to_enc
 	if (!block) return false;
 
 	if (!node) {
-		return blocks.every(block => block.global);
+		return block.global && blocks.every(block => block.global);
 	}
 
 	switch (block_might_apply_to_node(block, node)) {
@@ -208,7 +208,7 @@ function apply_selector(blocks: Block[], node: Element, stack: Element[], to_enc
 	return true;
 }
 
-function block_might_apply_to_node(block, node): BlockAppliesToNode {
+function block_might_apply_to_node(block: Block, node: Element): BlockAppliesToNode {
 	let i = block.selectors.length;
 
 	while (i--) {
diff --git a/test/css/samples/unused-selector-child-combinator/_config.js b/test/css/samples/unused-selector-child-combinator/_config.js
new file mode 100644
index 0000000000..becf382147
--- /dev/null
+++ b/test/css/samples/unused-selector-child-combinator/_config.js
@@ -0,0 +1,45 @@
+export default {
+	warnings: [
+		{
+			code: "css-unused-selector",
+			message: 'Unused CSS selector "article > *"',
+			frame: `
+			1: <style>
+			2:   article > * {
+			     ^
+			3:     font-size: 36px;
+			4:   }`,
+			pos: 10,
+			start: { character: 10, column: 1, line: 2 },
+			end: { character: 21, column: 12, line: 2 }
+		},
+		{
+			code: "css-unused-selector",
+			message: 'Unused CSS selector "article *"',
+			frame: `
+			4:   }
+			5:
+			6:   article * {
+			     ^
+			7:     font-size: 36px;
+			8:   }`,
+			pos: 49,
+			start: { character: 49, column: 1, line: 6 },
+			end: { character: 58, column: 10, line: 6 }
+		},
+		{
+			code: "css-unused-selector",
+			message: 'Unused CSS selector ".article > *"',
+			frame: `
+			 8:   }
+			 9:
+			10:   .article > * {
+			      ^
+			11:     font-size: 48px;
+			12:   }`,
+			pos: 86,
+			start: { character: 86, column: 1, line: 10 },
+			end: { character: 98, column: 13, line: 10 }
+		}
+	]
+};
diff --git a/test/css/samples/unused-selector-child-combinator/expected.css b/test/css/samples/unused-selector-child-combinator/expected.css
new file mode 100644
index 0000000000..68b778844f
--- /dev/null
+++ b/test/css/samples/unused-selector-child-combinator/expected.css
@@ -0,0 +1 @@
+div.svelte-xyz>.svelte-xyz{color:orange}
\ No newline at end of file
diff --git a/test/css/samples/unused-selector-child-combinator/input.svelte b/test/css/samples/unused-selector-child-combinator/input.svelte
new file mode 100644
index 0000000000..33a27e0465
--- /dev/null
+++ b/test/css/samples/unused-selector-child-combinator/input.svelte
@@ -0,0 +1,23 @@
+<style>	
+	article > * {
+		font-size: 36px;
+  }
+
+	article * {
+		font-size: 36px;
+	}
+	
+	.article > * {
+		font-size: 48px;
+	}
+	
+	div > * {
+		color: orange;
+	}
+</style>
+
+<div>
+	<p>
+		Svelte REPLs are svelte.
+	</p>
+</div>
\ No newline at end of file