Dereference null return value

If the function actually returns a null value, a null pointer dereference will occur. Return value of function which returns null is dereferenced without checking
/data/mci/2e33497b677d67d7791a7b674ab1a4f9/bazel_cache/4bf3abab731d485309854db752e57356/execroot/_main/src/mongo/db/catalog/rename_collection.cpp:419: NULL_RETURNS 174765 Assigning: "sourceColl" = "nullptr" return value from "lookupCollectionByNamespace".
/data/mci/2e33497b677d67d7791a7b674ab1a4f9/bazel_cache/4bf3abab731d485309854db752e57356/execroot/_main/src/mongo/db/catalog/rename_collection.cpp:423: NULL_RETURNS 174765 Dereferencing a pointer that might be "nullptr" "sourceColl" when calling "uuid". (The dereference happens because this is a virtual function call.)