Bug 244218

Summary:	mergemaster: audit the code to make sure -U still work without RCS ID
Product:	Base System	Reporter:	Xin LI <delphij>
Component:	bin	Assignee:	Xin LI <delphij>
Status:	Closed Works As Intended
Severity:	Affects Some People	CC:	bapt, emaste, gjb, glebius, imp, uqs
Priority:	---
Version:	CURRENT
Hardware:	Any
OS:	Any

Description Xin LI freebsd_committer

2020-02-18 21:00:38 UTC

We would like to make sure that mergemaster won't be affected when RCS ID is removed.

Comment 1 Xin LI freebsd_committer

2020-02-19 07:19:44 UTC

My conclusion is that $FreeBSD$ ID doesn't really matter for mergemaster.

For -U, the code basically sets AUTO_UPGRADE, which causes mergemaster to install new file if it's not user-modified (by comparing the current etc/ tree against saved mtree file).  It works regardless if $FreeBSD$ is present.

For -F, the code does a comparison with diff -q -I '[$]FreeBSD.*[$]' and installs new version if the file only differs in $FreeBSD$ tag.  If we stop expanding $FreeBSD$ or have it removed, the code would fall back to the traditional way of compare and when -U is present, it would correctly handle non-modified configuration files as usual.