repack: point out a bug handling stale shallow info

A `git fetch --prune` can turn previously-reachable objects unreachable, even commits that are in the `shallow` list. A subsequent `git repack -ad` will then unceremoniously drop those unreachable commits, and the `shallow` list will become stale. This means that when we try to fetch with a larger `--depth` the next time, we may end up with: fatal: error in object: unshallow <commit-hash> Reported by Alejandro Pauly. Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Johannes Schindelin committed Oct 24, 2018 at 08:56 UTC 328a43518244b970e1765eca78060bfeb265a584
1 file changed +27
t/t5537-fetch-shallow.sh
+27
@@ -186,6 +186,33 @@ EOF
186 test_cmp expect actual
187 '
188
189 +test_expect_failure '.git/shallow is edited by repack' '
190 + git init shallow-server &&
191 + test_commit -C shallow-server A &&
192 + test_commit -C shallow-server B &&
193 + git -C shallow-server checkout -b branch &&
194 + test_commit -C shallow-server C &&
195 + test_commit -C shallow-server E &&
196 + test_commit -C shallow-server D &&
197 + d="$(git -C shallow-server rev-parse --verify D^0)" &&
198 + git -C shallow-server checkout master &&
199 +
200 + git clone --depth=1 --no-tags --no-single-branch \
201 + "file://$PWD/shallow-server" shallow-client &&
202 +
203 + : now remove the branch and fetch with prune &&
204 + git -C shallow-server branch -D branch &&
205 + git -C shallow-client fetch --prune --depth=1 \
206 + origin "+refs/heads/*:refs/remotes/origin/*" &&
207 + git -C shallow-client repack -adfl &&
208 + test_must_fail git -C shallow-client rev-parse --verify $d^0 &&
209 + ! grep $d shallow-client/.git/shallow &&
210 +
211 + git -C shallow-server branch branch-orig $d &&
212 + git -C shallow-client fetch --prune --depth=2 \
213 + origin "+refs/heads/*:refs/remotes/origin/*"
214 +'
215 +
216 . "$TEST_DIRECTORY"/lib-httpd.sh
217 start_httpd
218