deconflict with implicit props - fixes #1957

src/compile/Component.ts

@@ -170,6 +170,7 @@ export default class Component {
 			const props = [...this.template_references];
 			this.declarations.push(...props);
 			addToSet(this.writable_declarations, this.template_references);
+			addToSet(this.userVars, this.template_references);
 
 			this.props = props.map(name => ({
 				name,

test/js/samples/deconflict-builtins/expected.js

@@ -1,5 +1,5 @@
 /* generated by Svelte vX.Y.Z */
-import { SvelteComponent as SvelteComponent_1, append, createComment, createElement, createText, destroyEach, detachNode, flush, init, insert, run, safe_not_equal, setData } from "svelte/internal";
+import { SvelteComponent as SvelteComponent_1, append, createComment, createElement as createElement_1, createText, destroyEach, detachNode, flush, init, insert, run, safe_not_equal, setData } from "svelte/internal";
 
 function get_each_context(ctx, list, i) {
 	const child_ctx = Object.create(ctx);
@@ -13,7 +13,7 @@ function create_each_block($$, ctx) {
 
 	return {
 		c() {
-			span = createElement("span");
+			span = createElement_1("span");
 			text = createText(text_value);
 		},
 

test/js/samples/select-dynamic-value/expected.js

@@ -2,7 +2,7 @@
 import { SvelteComponent as SvelteComponent_1, append, createElement, detachNode, flush, init, insert, run, safe_not_equal } from "svelte/internal";
 
 function create_fragment($$, ctx) {
-	var select, option0, option1, select_value_value, current;
+	var select, option0, option1, select_value_value, current_1;
 
 	return {
 		c() {
@@ -32,7 +32,7 @@ function create_fragment($$, ctx) {
 				}
 			}
 
-			current = true;
+			current_1 = true;
 		},
 
 		p(changed, ctx) {
@@ -49,7 +49,7 @@ function create_fragment($$, ctx) {
 		},
 
 		i(target, anchor) {
-			if (current) return;
+			if (current_1) return;
 			this.m(target, anchor);
 		},
 

test/runtime/samples/event-handler-deconflicted/_config.js

@@ -0,0 +1,11 @@
+export default {
+	preserveIdentifiers: true,
+
+	props: {
+		click_handler: 'x'
+	},
+
+	html: `
+		<button>x</button>
+	`
+};

test/runtime/samples/event-handler-deconflicted/main.html

@@ -0,0 +1 @@
+<button on:click="{() => foo()}">{click_handler}</button>