From f745ac75f1adbfc5dc4d1e4a8c365eb9463def01 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?F=C3=A1bio=20Santos?= <fabiosantosart@gmail.com>
Date: Sat, 4 Jun 2022 11:23:16 +0100
Subject: [PATCH] fix parsing of nested template strings. Closes #1204

---
 lib/ast.js                       |  9 +++++++++
 lib/parse.js                     | 17 +++++++++--------
 test/compress/template-string.js | 11 +++++++++++
 3 files changed, 29 insertions(+), 8 deletions(-)

diff --git a/lib/ast.js b/lib/ast.js
index 625999990..f7de7040e 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -93,6 +93,7 @@ const set_tok_flag = (tok, flag, truth) => {
 const TOK_FLAG_NLB          = 0b0001;
 const TOK_FLAG_QUOTE_SINGLE = 0b0010;
 const TOK_FLAG_QUOTE_EXISTS = 0b0100;
+const TOK_FLAG_TEMPLATE_END = 0b1000;
 
 class AST_Token {
     constructor(type, value, line, col, pos, nlb, comments_before, comments_after, file) {
@@ -128,6 +129,14 @@ class AST_Token {
         set_tok_flag(this, TOK_FLAG_QUOTE_SINGLE, quote_type === "'");
         set_tok_flag(this, TOK_FLAG_QUOTE_EXISTS, !!quote_type);
     }
+
+    get template_end() {
+        return has_tok_flag(this, TOK_FLAG_TEMPLATE_END);
+    }
+
+    set template_end(new_template_end) {
+        set_tok_flag(this, TOK_FLAG_TEMPLATE_END, new_template_end);
+    }
 }
 
 var AST_Node = DEFNODE("Node", "start end", function AST_Node(props) {
diff --git a/lib/parse.js b/lib/parse.js
index c99016a08..b1c22fb4f 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -162,7 +162,7 @@ import {
 } from "./ast.js";
 
 var LATEST_RAW = "";  // Only used for numbers and template strings
-var LATEST_TEMPLATE_END = true;
+var TEMPLATE_RAWS = new Map();  // Raw template strings
 
 var KEYWORDS = "break case catch class const continue debugger default delete do else export extends finally for function if in instanceof let new return switch throw try typeof var void while with";
 var KEYWORDS_ATOM = "false null true";
@@ -693,8 +693,8 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
                 next(true, true);
                 S.brace_counter++;
                 tok = token(begin ? "template_head" : "template_substitution", content);
-                LATEST_RAW = raw;
-                LATEST_TEMPLATE_END = false;
+                TEMPLATE_RAWS.set(tok, raw);
+                tok.template_end = false;
                 return tok;
             }
 
@@ -710,8 +710,8 @@ function tokenizer($TEXT, filename, html5_comments, shebang) {
         }
         S.template_braces.pop();
         tok = token(begin ? "template_head" : "template_substitution", content);
-        LATEST_RAW = raw;
-        LATEST_TEMPLATE_END = true;
+        TEMPLATE_RAWS.set(tok, raw);
+        tok.template_end = true;
         return tok;
     });
 
@@ -2367,19 +2367,19 @@ function parse($TEXT, options) {
 
         segments.push(new AST_TemplateSegment({
             start: S.token,
-            raw: LATEST_RAW,
+            raw: TEMPLATE_RAWS.get(S.token),
             value: S.token.value,
             end: S.token
         }));
 
-        while (!LATEST_TEMPLATE_END) {
+        while (!S.token.template_end) {
             next();
             handle_regexp();
             segments.push(expression(true));
 
             segments.push(new AST_TemplateSegment({
                 start: S.token,
-                raw: LATEST_RAW,
+                raw: TEMPLATE_RAWS.get(S.token),
                 value: S.token.value,
                 end: S.token
             }));
@@ -3342,6 +3342,7 @@ function parse($TEXT, options) {
         } else {
             toplevel = new AST_Toplevel({ start: start, body: body, end: end });
         }
+        TEMPLATE_RAWS = new Map();
         return toplevel;
     })();
 
diff --git a/test/compress/template-string.js b/test/compress/template-string.js
index 61e9079c1..61306b5a2 100644
--- a/test/compress/template-string.js
+++ b/test/compress/template-string.js
@@ -947,3 +947,14 @@ template_string_new_parens: {
     }
     expect_exact: "(new Thing)``;"
 }
+
+template_string_nested: {
+    input: {
+        console.log(`${`${2,0}`} ${1}`)
+        console.log(`${String.raw`${2,0}\n`} ${1}`)
+    }
+    expect_stdout: [
+        "0 1",
+        "0\\n 1",
+    ]
+}