Settle the snapshot v-prefix from the tag list

`compose_snapshot_prefix` dropped the leading v of a tag only when just
one of the names 1.2, v1.2 and V1.2 resolved as a tag, so that the
shorter snapshot name could always be traced back to one tag. Those
probes went through ref lookups, and on a case-insensitive filesystem
a lookup for V1.2 finds the loose file of v1.2, so every freshly made
tag counted as ambiguous and kept its v. Once git packed the refs the
lookups became exact and the same tag quietly changed its snapshot
names.

The claimants on a stripped name are now counted over the tag list
itself with exact string comparison, so the answer no longer depends
on how a ref is stored or on the filesystem underneath. Two tags that
really differ only by the letter's case still both keep it.

0 files changed, 0 insertions, 0 deletions