Fix Null-dereference READ
Fix Null-dereference READ

See https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=5472

Credit to oss-fuzz

StalderT/open62541,jpfr/open62541,StalderT/open62541,jpfr/open62541,JGrothoff/open62541,open62541/open62541,jpfr/open62541,StalderT/open62541,JGrothoff/open62541,JGrothoff/open62541,open62541/open62541,StalderT/open62541,open62541/open62541,jpfr/open62541,open62541/open62541,JGrothoff/open62541