From a419e508040dbf2654b9697ed73e3a7236b9160f Mon Sep 17 00:00:00 2001
From: greymoth <246701683+greymoth-jp@users.noreply.github.com>
Date: Tue, 30 Jun 2026 00:03:22 +0900
Subject: [PATCH] fix: parse "/*/" as an unclosed comment

The comment branch searches for the closing "*/" with
value.indexOf("*/", pos), starting at the same index as the opening
"/*". For the input "/*/" that search matches the "*" of the opening
delimiter plus the following "/", so the parser reports a closed empty
comment and never sets the unclosed flag. On stringify it then emits
"/**/", so the round trip is not lossless.

"/*/" is an unterminated comment, which postcss core also reports as an
unclosed comment. The parser already handles this for other inputs such
as "/*x"; only the slash right after the opener slipped through. Start
the closing search at pos + 2 so the opening "/*" cannot be matched as
its own terminator.
---
 lib/parse.js  |  2 +-
 test/parse.js | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/lib/parse.js b/lib/parse.js
index 7d343ca..48d2981 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -103,7 +103,7 @@ module.exports = function (input) {
 
       // Comments
     } else if (code === slash && value.charCodeAt(pos + 1) === star) {
-      next = value.indexOf("*/", pos);
+      next = value.indexOf("*/", pos + 2);
 
       token = {
         type: "comment",
diff --git a/test/parse.js b/test/parse.js
index 22aa393..02a2e59 100644
--- a/test/parse.js
+++ b/test/parse.js
@@ -1553,6 +1553,19 @@ const tests = [
       },
     ],
   },
+  {
+    message: "should not treat the opening slash-star as its own terminator",
+    fixture: "/*/",
+    expected: [
+      {
+        type: "comment",
+        sourceIndex: 0,
+        sourceEndIndex: 3,
+        value: "/",
+        unclosed: true,
+      },
+    ],
+  },
   {
     message: "should respect escape character",
     fixture: "Hawaii \\35 -0",