@matheusbsbs / matheus-bagliano / commits / eb398797cd

connect: advertized capability is not a ref

When cloning an empty repository served by standard git, "git clone" produces the following reassuring message: $ git clone git://localhost/tmp/empty Cloning into 'empty'... warning: You appear to have cloned an empty repository. Checking connectivity... done. Meanwhile when cloning an empty repository served by JGit, the output is more haphazard: $ git clone git://localhost/tmp/empty Cloning into 'empty'... Checking connectivity... done. warning: remote HEAD refers to nonexistent ref, unable to checkout. This is a common command to run immediately after creating a remote repository as preparation for adding content to populate it and pushing. The warning is confusing and needlessly worrying. The cause is that, since v3.1.0.201309270735-rc1~22 (Advertise capabilities with no refs in upload service., 2013-08-08), JGit's ref advertisement includes a ref named capabilities^{} to advertise its capabilities on, while git's ref advertisement is empty in this case. This allows the client to learn about the server's capabilities and is needed, for example, for fetch-by-sha1 to work when no refs are advertised. This also affects "ls-remote". For example, against an empty repository served by JGit: $ git ls-remote git://localhost/tmp/empty 0000000000000000000000000000000000000000 capabilities^{} Git advertises the same capabilities^{} ref in its ref advertisement for push but since it never did so for fetch, the client didn't need to handle this case. Handle it. Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Helped-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Jonathan Tan committed Sep 9, 2016 at 10:36 UTC eb398797cdc97aae15419f5ac1316440936c31f1
2 files changed +54
connect.c
+14
@@ -123,6 +123,7 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
123 * response does not necessarily mean an ACL problem, though.
124 */
125 int saw_response;
126 + int got_dummy_ref_with_capabilities_declaration = 0;
127
128 *list = NULL;
129 for (saw_response = 0; ; saw_response = 1) {
@@ -172,8 +173,21 @@ struct ref **get_remote_heads(int in, char *src_buf, size_t src_len,
173 continue;
174 }
175
176 + if (!strcmp(name, "capabilities^{}")) {
177 + if (saw_response)
178 + die("protocol error: unexpected capabilities^{}");
179 + if (got_dummy_ref_with_capabilities_declaration)
180 + die("protocol error: multiple capabilities^{}");
181 + got_dummy_ref_with_capabilities_declaration = 1;
182 + continue;
183 + }
184 +
185 if (!check_ref(name, flags))
186 continue;
187 +
188 + if (got_dummy_ref_with_capabilities_declaration)
189 + die("protocol error: unexpected ref after capabilities^{}");
190 +
191 ref = alloc_ref(buffer + GIT_SHA1_HEXSZ + 1);
192 oidcpy(&ref->old_oid, &old_oid);
193 *list = ref;
t/t5512-ls-remote.sh
+40
@@ -207,5 +207,45 @@ test_expect_success 'ls-remote --symref omits filtered-out matches' '
207 test_cmp expect actual
208 '
209
210 +test_lazy_prereq GIT_DAEMON '
211 + test_tristate GIT_TEST_GIT_DAEMON &&
212 + test "$GIT_TEST_GIT_DAEMON" != false
213 +'
214 +
215 +# This test spawns a daemon, so run it only if the user would be OK with
216 +# testing with git-daemon.
217 +test_expect_success PIPE,JGIT,GIT_DAEMON 'indicate no refs in standards-compliant empty remote' '
218 + JGIT_DAEMON_PORT=${JGIT_DAEMON_PORT-${this_test#t}} &&
219 + JGIT_DAEMON_PID= &&
220 + git init --bare empty.git &&
221 + >empty.git/git-daemon-export-ok &&
222 + mkfifo jgit_daemon_output &&
223 + {
224 + jgit daemon --port="$JGIT_DAEMON_PORT" . >jgit_daemon_output &
225 + JGIT_DAEMON_PID=$!
226 + } &&
227 + test_when_finished kill "$JGIT_DAEMON_PID" &&
228 + {
229 + read line &&
230 + case $line in
231 + Exporting*)
232 + ;;
233 + *)
234 + echo "Expected: Exporting" &&
235 + false;;
236 + esac &&
237 + read line &&
238 + case $line in
239 + "Listening on"*)
240 + ;;
241 + *)
242 + echo "Expected: Listening on" &&
243 + false;;
244 + esac
245 + } <jgit_daemon_output &&
246 + # --exit-code asks the command to exit with 2 when no
247 + # matching refs are found.
248 + test_expect_code 2 git ls-remote --exit-code git://localhost:$JGIT_DAEMON_PORT/empty.git
249 +'
250
251 test_done