From 790f2b53131f2468ee9b7884a4a361ae6f4d6cc0 Mon Sep 17 00:00:00 2001
From: Christian Kaisermann <christian@kaisermann.me>
Date: Mon, 20 Aug 2018 22:39:32 -0300
Subject: [PATCH] Remove an undefined attribute instead of setting it to
 "undefined" (string)

---
 src/shared/dom.js                                  |  8 ++++----
 test/runtime/samples/set-undefined-attr/_config.js |  5 +++++
 test/runtime/samples/set-undefined-attr/main.html  | 14 ++++++++++++++
 3 files changed, 23 insertions(+), 4 deletions(-)
 create mode 100644 test/runtime/samples/set-undefined-attr/_config.js
 create mode 100644 test/runtime/samples/set-undefined-attr/main.html

diff --git a/src/shared/dom.js b/src/shared/dom.js
index d428e92f1c..5e152b9c1b 100644
--- a/src/shared/dom.js
+++ b/src/shared/dom.js
@@ -82,7 +82,8 @@ export function removeListener(node, event, handler) {
 }
 
 export function setAttribute(node, attribute, value) {
-	node.setAttribute(attribute, value);
+	if (value === undefined) removeAttribute(node, attribute);
+	else node.setAttribute(attribute, value);
 }
 
 export function setAttributes(node, attributes) {
@@ -90,8 +91,7 @@ export function setAttributes(node, attributes) {
 		if (key in node) {
 			node[key] = attributes[key];
 		} else {
-			if (attributes[key] === undefined) removeAttribute(node, key);
-			else setAttribute(node, key, attributes[key]);
+			setAttribute(node, key, attributes[key]);
 		}
 	}
 }
@@ -238,4 +238,4 @@ export function addResizeListener(element, fn) {
 			element.removeChild(object);
 		}
 	};
-}
\ No newline at end of file
+}
diff --git a/test/runtime/samples/set-undefined-attr/_config.js b/test/runtime/samples/set-undefined-attr/_config.js
new file mode 100644
index 0000000000..d5aa293bf2
--- /dev/null
+++ b/test/runtime/samples/set-undefined-attr/_config.js
@@ -0,0 +1,5 @@
+export default {
+	'skip-ssr': true,
+
+	html: '<div></div>'
+};
diff --git a/test/runtime/samples/set-undefined-attr/main.html b/test/runtime/samples/set-undefined-attr/main.html
new file mode 100644
index 0000000000..09e63ca45b
--- /dev/null
+++ b/test/runtime/samples/set-undefined-attr/main.html
@@ -0,0 +1,14 @@
+<div {foo} {bar}></div>
+
+<script>
+	export default {
+		data: () => ({
+			foo: 1,
+			bar: undefined
+		}),
+
+		oncreate () {
+			this.set({ foo: undefined });
+		}
+	};
+</script>