fix(fslib): handle .zip in the middle of file name again

packages/yarnpkg-fslib/sources/ZipOpenFS.ts

@@ -21,20 +21,20 @@ const DOT_ZIP = `.zip`;
  * The indexOf-based implementation is ~3.7x faster than a RegExp-based implementation.
  */
 export const getArchivePart = (path: string) => {
-  const idx = path.indexOf(DOT_ZIP);
+  let idx = path.indexOf(DOT_ZIP);
   if (idx <= 0)
     return null;
 
-  // Disallow files named ".zip"
-  if (path[idx - 1] === ppath.sep)
-    return null;
-
-  let nextCharIdx = idx + DOT_ZIP.length;
-  const idxBeforeSep = path.indexOf(ppath.sep, nextCharIdx);
-  if (idxBeforeSep >= 0)
-    nextCharIdx = idxBeforeSep;
-  else if (path.endsWith(DOT_ZIP))
-    nextCharIdx = path.length;
+  let nextCharIdx = idx;
+  while (idx >= 0) {
+    nextCharIdx = idx + DOT_ZIP.length;
+    if (path[nextCharIdx] === ppath.sep)
+      break;
+    // Disallow files named ".zip"
+    if (path[idx - 1] === ppath.sep)
+      return null;
+    idx = path.indexOf(DOT_ZIP, nextCharIdx);
+  }
 
   // The path either has to end in ".zip" or contain an archive subpath (".zip/...")
   if (path.length > nextCharIdx && path[nextCharIdx] !== ppath.sep)