pull: Support deltas for explicit commits

I think the majority of OSTree usage calls pull with refs, not
explicit commits.  We even added special "override syntax" with
`@` (e.g. `ostree pull foo@ab12c34`) as a hybrid.

However, some users may want to still pull explicit commits
for whatever reason.  The old static delta logic looked at
the previous commit of the ref.  However, in https://github.com/ostreedev/ostree/pull/710
we enhanced the logic to look at all local commits.

It's now a lot more natural to teach the delta logic
to support revisions, e.g. `ostree pull someorigin ab12c34`.

This also fixes the problem that before, `--require-static-deltas`
was completely ignored when processing revisions.

This is a nontrivial refactoring of the logic, but the end
result feels a lot more readable to me.

Closes: https://github.com/ostreedev/ostree/issues/783

Closes: #787
Approved by: cgwalters

tests/pull-test.sh

@@ -35,7 +35,7 @@ function verify_initial_contents() {
     assert_file_has_content baz/cow '^moo$'
 }
 
-echo "1..15"
+echo "1..16"
 
 # Try both syntaxes
 repo_init
@@ -150,23 +150,33 @@ prev_rev=$(ostree --repo=ostree-srv/gnomerepo rev-parse main^)
 new_rev=$(ostree --repo=ostree-srv/gnomerepo rev-parse main)
 ${CMD_PREFIX} ostree --repo=ostree-srv/gnomerepo summary -u
 
+# Explicitly test delta fetches via ref name as well as commit hash
+for delta_target in main ${new_rev}; do
 cd ${test_tmpdir}
 repo_init
 ${CMD_PREFIX} ostree --repo=repo pull origin main@${prev_rev}
-${CMD_PREFIX} ostree --repo=repo pull --dry-run --require-static-deltas origin main >dry-run-pull.txt
+${CMD_PREFIX} ostree --repo=repo pull --dry-run --require-static-deltas origin ${delta_target} >dry-run-pull.txt
 # Compression can vary, so we support 400-699
 assert_file_has_content dry-run-pull.txt 'Delta update: 0/1 parts, 0 bytes/[456][0-9][0-9] bytes, 455 bytes total uncompressed'
 rev=$(${CMD_PREFIX} ostree --repo=repo rev-parse origin:main)
 assert_streq "${prev_rev}" "${rev}"
 ${CMD_PREFIX} ostree --repo=repo fsck
+done
 
+# Explicitly test delta fetches via ref name as well as commit hash
+for delta_target in main ${new_rev}; do
 cd ${test_tmpdir}
 repo_init
 ${CMD_PREFIX} ostree --repo=repo pull origin main@${prev_rev}
-${CMD_PREFIX} ostree --repo=repo pull --require-static-deltas origin main
-rev=$(${CMD_PREFIX} ostree --repo=repo rev-parse origin:main)
-assert_streq "${new_rev}" "${rev}"
+${CMD_PREFIX} ostree --repo=repo pull --require-static-deltas origin ${delta_target}
+if test ${delta_target} = main; then
+    rev=$(${CMD_PREFIX} ostree --repo=repo rev-parse origin:main)
+    assert_streq "${new_rev}" "${rev}"
+else
+    ${CMD_PREFIX} ostree --repo=repo rev-parse ${delta_target}
+fi
 ${CMD_PREFIX} ostree --repo=repo fsck
+done
 
 cd ${test_tmpdir}
 repo_init
@@ -208,8 +218,23 @@ fi
 assert_file_has_content err.txt "deltas required, but none found"
 ${CMD_PREFIX} ostree --repo=repo fsck
 
+# Now test with a partial commit
+repo_init
+${CMD_PREFIX} ostree --repo=repo pull --commit-metadata-only origin main@${prev_rev}
+if ${CMD_PREFIX} ostree --repo=repo pull --require-static-deltas origin main 2>err.txt; then
+    assert_not_reached "--require-static-deltas unexpectedly succeeded"
+fi
+assert_file_has_content err.txt "deltas required, but none found"
 echo "ok delta required but don't exist"
 
+repo_init
+${CMD_PREFIX} ostree --repo=repo pull origin main@${prev_rev}
+if ${CMD_PREFIX} ostree --repo=repo pull --require-static-deltas origin ${new_rev} 2>err.txt; then
+    assert_not_reached "--require-static-deltas unexpectedly succeeded"
+fi
+assert_file_has_content err.txt "deltas required, but none found"
+echo "ok delta required for revision"
+
 cd ${test_tmpdir}
 rm main-files -rf
 ${CMD_PREFIX} ostree --repo=ostree-srv/gnomerepo checkout main main-files

tests/test-delta.sh

@@ -169,9 +169,9 @@ echo 'ok heuristic endian detection'
 ${CMD_PREFIX} ostree --repo=repo summary -u
 
 mkdir repo2 && ostree_repo_init repo2 --mode=bare-user
-${CMD_PREFIX} ostree --repo=repo2 pull-local --require-static-deltas repo ${newrev}
+${CMD_PREFIX} ostree --repo=repo2 pull-local --require-static-deltas repo ${origrev}
 ${CMD_PREFIX} ostree --repo=repo2 fsck
-${CMD_PREFIX} ostree --repo=repo2 ls ${newrev} >/dev/null
+${CMD_PREFIX} ostree --repo=repo2 ls ${origrev} >/dev/null
 
 echo 'ok pull delta'