Update NEWS.md

Co-authored-by: Michael Chirico <[email protected]>

Author: ben-schwen

NEWS.md

@@ -16,7 +16,7 @@
 
 4. `as.data.table()` now properly handles keys: specifying keys sets them, omitting keys preserves existing ones, and setting `key=NULL` clears them, [#6859](https://github.com/Rdatatable/data.table/issues/6859). Thanks @brookslogan for the report and @Mukulyadav2004 for the fix.
 
-5. `as.data.table.data.frame(x)` could enter an infinity loop if the S3 method for `as.data.frame(x)` was overridden without ensuring `class(as.data.frame(x)) == "data.frame"`, [#6874](https://github.com/Rdatatable/data.table/issues/6874). Thanks @matschmitz for the report and @ben-schwen for the fix.
+5. `as.data.table()` on `x` avoids an infinite loop if the output of the corresponding `as.data.frame()` method has the same class as the input, [#6874](https://github.com/Rdatatable/data.table/issues/6874). Concretely, we had `class(x) = c('foo', 'data.frame')` and `class(as.data.frame(x)) = c('foo', 'data.frame')`, so `as.data.frame.foo` wound up getting called repeatedly. Thanks @matschmitz for the report and @ben-schwen for the fix.
 
 ## NOTES