Commit d9766ddc3d525cf08acec4c3483e61d86c9899a8 (Qt 5.12) replaced the use of the old binary JSON format with CBOR, which is more compact and standard, but requires actual parsing instead of just a quick size verification. For regular, loaded plugins, the metadata is stored in parsed QCborValue format, but for static plugins, we were re-parsing each staticplugin's metadata for every single call. This avoids a full parsing and only parses the CBOR header to find the IIDs (moc always outputs the IID first). Fixes: QTBUG-114253 Pick-to: 6.6 Change-Id: I8bd6bb457b9c42218247fffd179750ec6c9e3252 Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io> Reviewed-by: Thiago Macieira <thiago.macieira@intel.com> Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>