coverity scan issue in new deferred memberof code

[progier389]

Issue Description
Weekly Coverity scan report
detected 3 issues related to recent commit about deferred memberof code:

https://scan6.scan.coverity.com/#/project-view/58468/11545?selectedIssue=1562483 (null pointer dereference)
https://scan6.scan.coverity.com/#/project-view/58468/11545?selectedIssue=1562482 (memory leak)
https://scan6.scan.coverity.com/#/project-view/58468/11545?selectedIssue=1562481 (double free)

[droideck]

https://scan6.scan.coverity.com/#/project-view/60005/11545?selectedIssue=1563307 (null pointer dereference)
https://scan6.scan.coverity.com/#/project-view/60005/11545?selectedIssue=1563306 (race condition)

[mreynolds389]

@progier389 @tbordaz Does this impact all versions? The original PR was merged all the way down to 1.4.3, and this covscan fix was only pushed to main.