multiple -m

sync, assist, import: Allow -m option to be specified multiple times, to
provide additional paragraphs for the commit message.

The option parser didn't allow multiple -m before, so there is no risk of
behavior change breaking something that was for some reason using multiple
-m already.

Pass through to git commands, so that the method used to assemble the
paragrahs is whatever git does. Which might conceivably change in the
future.

Note that git commit-tree has supported -m since git 1.7.7. commitTree
was probably not using it since it predates that version. Since the
configure script prevents building git-annex with git older than 2.1,
there is no risk that it's not supported now.

Sponsored-by: Nicholas Golder-Manning on Patreon

Annex/AdjustedBranch/Merge.hs

@@ -153,7 +153,8 @@ mergeToAdjustedBranch tomerge (origbranch, adj) mergeconfig canresolvemerge comm
 			then do
 				cmode <- annexCommitMode <$> Annex.getGitConfig
 				c <- inRepo $ Git.Branch.commitTree cmode
-					("Merged " ++ fromRef tomerge) [adjmergecommit]
+					["Merged " ++ fromRef tomerge]
+					[adjmergecommit]
 					(commitTree currentcommit)
 				inRepo $ Git.Branch.update "updating adjusted branch" currbranch c
 				propigateAdjustedCommits origbranch adj