Merge branch 'master' into preferred

doc/todo/import_from_special_remote_large_git_log.mdwn

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+After import from a special remote and merge, git log --stat shows
+a large diff, because every file that got imported from the special 
+remote is put on a commit with no parent, so the diff shows it as if those
+files are newly added.
+
+(Of course when using S3 with versioning, the commit tree does have
+parents, but still a root commit with no parent.)
+
+This does not seem avoidable for the initial import, even if the remote was
+populated by an earlier export, that starts a new, disconnected history for
+reasons explained in the import tree design. 
+
+Subsequent imports though could fix it, by setting the parent of the new
+import to the previous import.
+
+For versioned imports, it reuses commits from the old imported history,
+and adds more commits on top of those, so this is mostly not a problem
+there. If the old and new imported histories are disjoint, a commit or
+commits will be made with no parent, but that seems acceptable; it's an
+edge case and it's replicating the information from the remote.
+
+> [[done]] --[[Joey]]