From: Antonin Delpeuch <antonin@delpeuch.eu>

Custom merge drivers need access to the names of the revisions they
are working on, so that the merge conflict markers they introduce
can refer to those revisions. The placeholders '%S', '%X' and '%Y'
are introduced to this end.

Signed-off-by: Antonin Delpeuch <antonin@delpeuch.eu>

Submitted-As: https://lore.kernel.org/git/pull.1648.v4.git.git.1706126951879.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1648.git.git.1705587974840.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1648.v2.git.git.1705592581272.gitgitgadget@gmail.com
In-Reply-To: https://lore.kernel.org/git/pull.1648.v3.git.git.1705615794307.gitgitgadget@gmail.com