Let's mimic git.git auto tag fetch behavior.

Related to https://github.com/libgit2/libgit2sharp/pull/927/files#r23450279

git fetch against a newly initialized repository with the following config

[core]
    repositoryformatversion = 0
    filemode = false
    bare = false
    logallrefupdates = true
    symlinks = false
    ignorecase = true
    hideDotFiles = dotGitOnly
[remote "origin"]
    url = https://github.com/libgit2/TestGitRepository
    fetch = +refs/heads/*:refs/remotes/origin/*

outputs

$ git fetch
remote: Counting objects: 68, done.
remote: Total 68 (delta 0), reused 0 (delta 0)
Unpacking objects: 100% (68/68), done.
From https://github.com/libgit2/TestGitRepository
 * [new branch]      first-merge -> origin/first-merge
 * [new branch]      master     -> origin/master
 * [new branch]      no-parent  -> origin/no-parent
remote: Counting objects: 1, done.
remote: Total 1 (delta 0), reused 1 (delta 0)
Unpacking objects: 100% (1/1), done.
 * [new tag]         annotated_tag -> annotated_tag
 * [new tag]         blob       -> blob
 * [new tag]         commit_tree -> commit_tree

git is noticing that the server did not automatically send the tags and is performing a second fetch. This second fetch is completely different from the first one

En el issue no se nombra ningún archivo de código fuente ni ninguna prueba. Empieza localizando la implementación de fetch y sus pruebas de fetch existentes; después, compara el fetch inicial con el fetch posterior de tags de Git cuando el servidor no envía los tags automáticamente. Se considera completado cuando se reproduce el comportamiento demostrado de dos fetch y se informa de los tags recién obtenidos.