The bool number = false parameter of putString() overloads is not only a classical Bool Trap (ie. doesn't give any hint to the reader of a call what 'true' or 'false' means), it also, in combination with the (ptr, n, bool=false) and (view, bool=false) overloading may cause a (ptr, n) argument list to accidentally match (view, number) instead: if decltype(ptr) isn't (const) QChar*, but one of the views accepts the type in it's (Char*) ctor, the call might be solved as (View(ptr), bool number(n)). This is not acceptable for a security-critical component. To fix, introduce a strong enum, PutStringMode { String, Number } to replace the bool. Only after this change it is safe to remove the (unused) (ptr, n, bool) overload, for the above-mentioned reason, so do it now. The alternative was to split putString() into putString() and putNumber(), but there's already a putNumber(qulonglong, bool negative), so I opted for an enum argument instead. Fixes: QTBUG-138520 Pick-to: 6.10 6.9 6.8 6.5 Change-Id: I78d1a9132d5ef41e33b9462d48d2f41401e1f688 Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>