Go to file
Jeff King 968f12fdac refs: turn on GIT_REF_PARANOIA by default
The original point of the GIT_REF_PARANOIA flag was to include broken
refs in iterations, so that possibly-destructive operations would not
silently ignore them (and would generally instead try to operate on the
oids and fail when the objects could not be accessed).

We already turned this on by default for some dangerous operations, like
"repack -ad" (where missing a reachability tip would mean dropping the
associated history). But it was not on for general use, even though it
could easily result in the spreading of corruption (e.g., imagine
cloning a repository which simply omits some of its refs because
their objects are missing; the result quietly succeeds even though you
did not clone everything!).

This patch turns on GIT_REF_PARANOIA by default. So a clone as mentioned
above would actually fail (upload-pack tells us about the broken ref,
and when we ask for the objects, pack-objects fails to deliver them).
This may be inconvenient when working with a corrupted repository, but:

  - we are better off to err on the side of complaining about
    corruption, and then provide mechanisms for explicitly loosening
    safety.

  - this is only one type of corruption anyway. If we are missing any
    other objects in the history that _aren't_ ref tips, then we'd
    behave similarly (happily show the ref, but then barf when we
    started traversing).

We retain the GIT_REF_PARANOIA variable, but simply default it to "1"
instead of "0". That gives the user an escape hatch for loosening this
when working with a corrupt repository. It won't work across a remote
connection to upload-pack (because we can't necessarily set environment
variables on the remote), but there the client has other options (e.g.,
choosing which refs to fetch).

As a bonus, this also makes ref iteration faster in general (because we
don't have to call has_object_file() for each ref), though probably not
noticeably so in the general case. In a repo with a million refs, it
shaved a few hundred milliseconds off of upload-pack's advertisement;
that's noticeable, but most repos are not nearly that large.

The possible downside here is that any operation which iterates refs but
doesn't ever open their objects may now quietly claim to have X when the
object is corrupted (e.g., "git rev-list new-branch --not --all" will
treat a broken ref as uninteresting). But again, that's not really any
different than corruption below the ref level. We might have
refs/heads/old-branch as non-corrupt, but we are not actively checking
that we have the entire reachable history. Or the pointed-to object
could even be corrupted on-disk (but our "do we have it" check would
still succeed). In that sense, this is merely bringing ref-corruption in
line with general object corruption.

One alternative implementation would be to actually check for broken
refs, and then _immediately die_ if we see any. That would cause the
"rev-list --not --all" case above to abort immediately. But in many ways
that's the worst of all worlds:

  - it still spends time looking up the objects an extra time

  - it still doesn't catch corruption below the ref level

  - it's even more inconvenient; with the current implementation of
    GIT_REF_PARANOIA for something like upload-pack, we can make
    the advertisement and let the client choose a non-broken piece of
    history. If we bail as soon as we see a broken ref, they cannot even
    see the advertisement.

The test changes here show some of the fallout. A non-destructive "git
repack -adk" now fails by default (but we can override it). Deleting a
broken ref now actually tells the hooks the correct "before" state,
rather than a confusing null oid.

Signed-off-by: Jeff King <peff@peff.net>
Reviewed-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-09-27 12:36:45 -07:00
.github Merge branch 'cb/ci-build-pedantic' 2021-09-10 11:46:32 -07:00
Documentation refs: turn on GIT_REF_PARANOIA by default 2021-09-27 12:36:45 -07:00
block-sha1
builtin Merge branch 'rs/use-xopen-in-index-pack' 2021-09-23 13:44:50 -07:00
ci Merge branch 'tb/multi-pack-bitmaps' 2021-09-20 15:20:39 -07:00
compat Merge branch 'cb/pedantic-build-for-developers' 2021-09-20 15:20:41 -07:00
contrib Merge branch 'rs/use-xopen-in-index-pack' 2021-09-23 13:44:50 -07:00
ewah
git-gui
gitk-git
gitweb Merge branch 'gh/gitweb-branch-sort' 2021-09-10 11:46:32 -07:00
mergetools
negotiator
perl
po l10n: sv.po: Update Swedish translation (5230t0f0u) 2021-08-16 06:54:20 +08:00
ppc
refs refs: add DO_FOR_EACH_OMIT_DANGLING_SYMREFS flag 2021-09-27 12:36:45 -07:00
sha1collisiondetection@855827c583
sha1dc
sha256
t refs: turn on GIT_REF_PARANOIA by default 2021-09-27 12:36:45 -07:00
templates
trace2 tr2: stop leaking "thread_name" memory 2021-09-07 11:07:59 -07:00
xdiff
.cirrus.yml ci: update freebsd 12 cirrus job 2021-08-12 14:00:52 -07:00
.clang-format
.editorconfig
.gitattributes
.gitignore
.gitmodules
.mailmap
.travis.yml
.tsan-suppressions
CODE_OF_CONDUCT.md
COPYING
GIT-VERSION-GEN The first batch post 2.33 2021-08-24 15:33:23 -07:00
INSTALL INSTALL: mention that we need libcurl 7.19.4 or newer to build 2021-09-13 10:39:03 -07:00
LGPL-2.1
Makefile Merge branch 'ab/http-drop-old-curl-plus' 2021-09-23 13:44:47 -07:00
README.md
RelNotes The first batch post 2.33 2021-08-24 15:33:23 -07:00
SECURITY.md
abspath.c
aclocal.m4
add-interactive.c
add-interactive.h
add-patch.c
advice.c Merge branch 'ab/retire-advice-config' 2021-09-10 11:46:29 -07:00
advice.h Merge branch 'ab/retire-advice-config' 2021-09-10 11:46:29 -07:00
alias.c
alias.h
alloc.c
alloc.h
apply.c Merge branch 'jc/trivial-threeway-binary-merge' 2021-09-15 13:15:26 -07:00
apply.h
archive-tar.c
archive-zip.c
archive.c archive: convert queue_directory to struct object_id 2021-08-27 14:19:00 -07:00
archive.h
attr.c attr: be careful about sparse directories 2021-09-07 22:41:10 -07:00
attr.h
banned.h
base85.c
bisect.c
bisect.h
blame.c
blame.h
blob.c
blob.h
bloom.c
bloom.h
branch.c advice: remove read uses of most global `advice_` variables 2021-08-25 12:07:52 -07:00
branch.h
builtin.h
bulk-checkin.c pack-write: split up finish_tmp_packfile() function 2021-09-09 18:23:11 -07:00
bulk-checkin.h
bundle.c bundle API: change "flags" to be "extra_index_pack_args" 2021-09-07 10:59:23 -07:00
bundle.h bundle API: change "flags" to be "extra_index_pack_args" 2021-09-07 10:59:23 -07:00
cache-tree.c
cache-tree.h
cache.h Merge branch 'rs/drop-core-compression-vars' 2021-09-23 13:44:46 -07:00
cbtree.c
cbtree.h oidtree: avoid unaligned access to crit-bit tree 2021-08-15 13:13:50 -07:00
chdir-notify.c
chdir-notify.h
check-builtins.sh
checkout.c
checkout.h
chunk-format.c
chunk-format.h
color.c
color.h
column.c
column.h
combine-diff.c
command-list.txt
commit-graph.c Merge branch 'js/run-command-close-packs' 2021-09-20 15:20:45 -07:00
commit-graph.h
commit-reach.c
commit-reach.h
commit-slab-decl.h
commit-slab-impl.h
commit-slab.h
commit.c advice: move advice.graftFileDeprecated squashing to commit.[ch] 2021-08-25 12:07:52 -07:00
commit.h advice: move advice.graftFileDeprecated squashing to commit.[ch] 2021-08-25 12:07:52 -07:00
common-main.c
config.c Merge branch 'rs/drop-core-compression-vars' 2021-09-23 13:44:46 -07:00
config.h submodule-config: pass repo upon blob config read 2021-09-08 11:48:09 -07:00
config.mak.dev developer: enable pedantic by default 2021-09-03 11:40:30 -07:00
config.mak.in
config.mak.uname Merge branch 'es/trace2-log-parent-process-name' 2021-08-24 15:32:40 -07:00
configure.ac
connect.c
connect.h
connected.c Merge branch 'ps/fetch-optim' 2021-09-20 15:20:39 -07:00
connected.h connected: refactor iterator to return next object ID directly 2021-09-01 12:43:56 -07:00
convert.c
convert.h
copy.c
credential.c credential: fix leak in credential_apply_config() 2021-08-25 11:41:30 -07:00
credential.h
csum-file.c use xopen() to handle fatal open(2) failures 2021-08-25 14:39:08 -07:00
csum-file.h
ctype.c
daemon.c
date.c
decorate.c
decorate.h
delta-islands.c
delta-islands.h
delta.h
detect-compiler
diff-delta.c
diff-lib.c Merge branch 'dd/diff-files-unmerged-fix' 2021-09-08 13:30:31 -07:00
diff-merges.c diff-index: restore -c/--cc options handling 2021-09-07 11:11:35 -07:00
diff-merges.h diff-index: restore -c/--cc options handling 2021-09-07 11:11:35 -07:00
diff-no-index.c
diff.c diff: ignore sparse paths in diffstat 2021-09-09 15:49:04 -07:00
diff.h
diffcore-break.c
diffcore-delta.c
diffcore-order.c
diffcore-pickaxe.c
diffcore-rename.c Merge branch 'en/ort-perf-batch-15' 2021-08-24 15:32:39 -07:00
diffcore-rotate.c
diffcore.h
dir-iterator.c
dir-iterator.h
dir.c Merge branch 'jt/submodule-name-to-gitdir' 2021-09-23 13:44:49 -07:00
dir.h Merge branch 'ds/sparse-index-ignored-files' 2021-09-20 15:20:44 -07:00
editor.c advice: remove read uses of most global `advice_` variables 2021-08-25 12:07:52 -07:00
entry.c entry: show finer-grained counter in "Filtering content" progress line 2021-09-09 09:58:19 -07:00
entry.h checkout: make delayed checkout respect --quiet and --no-progress 2021-08-26 23:15:33 -07:00
environment.c compression: drop write-only core_compression_* variables 2021-09-12 16:23:28 -07:00
environment.h
exec-cmd.c
exec-cmd.h
fetch-negotiator.c
fetch-negotiator.h
fetch-pack.c fetch-pack: optimize loading of refs via commit graph 2021-09-01 12:43:56 -07:00
fetch-pack.h
fmt-merge-msg.c
fmt-merge-msg.h
fsck.c
fsck.h
fsmonitor.c
fsmonitor.h
fuzz-commit-graph.c
fuzz-pack-headers.c
fuzz-pack-idx.c
generate-cmdlist.sh
generate-configlist.sh
gettext.c
gettext.h gettext: remove optional non-standard parens in N_() definition 2021-09-03 11:40:30 -07:00
git-add--interactive.perl
git-archimport.perl
git-bisect.sh Merge branch 'mr/bisect-in-c-4' 2021-09-23 13:44:48 -07:00
git-compat-util.h Merge branch 'cb/unix-sockets-with-windows' 2021-09-23 13:44:48 -07:00
git-curl-compat.h http: don't hardcode the value of CURL_SOCKOPT_OK 2021-09-13 10:39:04 -07:00
git-cvsexportcommit.perl
git-cvsimport.perl
git-cvsserver.perl
git-difftool--helper.sh
git-filter-branch.sh
git-instaweb.sh
git-merge-octopus.sh
git-merge-one-file.sh
git-merge-resolve.sh
git-mergetool--lib.sh
git-mergetool.sh
git-p4.py
git-quiltimport.sh
git-rebase--preserve-merges.sh
git-request-pull.sh
git-send-email.perl Merge branch 'ab/send-email-config-fix' 2021-09-15 13:15:24 -07:00
git-sh-i18n.sh
git-sh-setup.sh git-sh-setup: remove unused "pull with rebase" message 2021-09-12 16:22:05 -07:00
git-submodule.sh Merge branch 'ab/unused-script-helpers' 2021-09-23 13:44:47 -07:00
git-svn.perl
git-web--browse.sh
git.c midx: disallow running outside of a repository 2021-09-01 10:58:43 -07:00
git.rc
gpg-interface.c
gpg-interface.h
graph.c
graph.h
grep.c grep: add repository to OID grep sources 2021-09-08 11:48:05 -07:00
grep.h grep: add repository to OID grep sources 2021-09-08 11:48:05 -07:00
hash-lookup.c
hash-lookup.h
hash.h oidtree: avoid unaligned access to crit-bit tree 2021-08-15 13:13:50 -07:00
hashmap.c
hashmap.h
help.c help.c: help.autocorrect=prompt waits for user action 2021-08-14 11:20:49 -07:00
help.h
hex.c
http-backend.c Merge branch 'jk/http-server-protocol-versions' 2021-09-23 13:44:47 -07:00
http-fetch.c
http-push.c
http-walker.c
http.c http: don't hardcode the value of CURL_SOCKOPT_OK 2021-09-13 10:39:04 -07:00
http.h
ident.c
imap-send.c http: centralize the accounting of libcurl dependencies 2021-09-13 10:39:04 -07:00
iterator.h
json-writer.c
json-writer.h
khash.h
kwset.c
kwset.h
levenshtein.c
levenshtein.h
line-log.c
line-log.h
line-range.c
line-range.h
linear-assignment.c
linear-assignment.h
list-objects-filter-options.c
list-objects-filter-options.h
list-objects-filter.c
list-objects-filter.h
list-objects.c list-objects.c: rename "traverse_trees_and_blobs" to "traverse_non_commits" 2021-08-12 13:08:30 -07:00
list-objects.h
list.h
ll-merge.c
ll-merge.h
lockfile.c
lockfile.h
log-tree.c
log-tree.h
ls-refs.c Merge branch 'ab/serve-cleanup' 2021-09-20 15:20:43 -07:00
ls-refs.h
mailinfo.c
mailinfo.h
mailmap.c Merge branch 'ab/mailmap-leakfix' 2021-09-10 11:46:28 -07:00
mailmap.h
match-trees.c
mem-pool.c
mem-pool.h
merge-blobs.c
merge-blobs.h
merge-ort-wrappers.c
merge-ort-wrappers.h
merge-ort.c Merge branch 'ds/mergies-with-sparse-index' 2021-09-20 15:20:45 -07:00
merge-ort.h
merge-recursive.c Merge branch 'ds/mergies-with-sparse-index' 2021-09-20 15:20:45 -07:00
merge-recursive.h
merge.c
mergesort.c
mergesort.h
midx.c Merge branch 'rs/packfile-bad-object-list-in-oidset' 2021-09-23 13:44:46 -07:00
midx.h midx: respect 'GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP' 2021-09-01 13:56:43 -07:00
name-hash.c
notes-cache.c
notes-cache.h
notes-merge.c advice: remove read uses of most global `advice_` variables 2021-08-25 12:07:52 -07:00
notes-merge.h
notes-utils.c
notes-utils.h
notes.c
notes.h
object-file.c Merge branch 'rs/packfile-bad-object-list-in-oidset' 2021-09-23 13:44:46 -07:00
object-name.c advice: remove read uses of most global `advice_` variables 2021-08-25 12:07:52 -07:00
object-store.h Merge branch 'rs/packfile-bad-object-list-in-oidset' 2021-09-23 13:44:46 -07:00
object.c
object.h builtin/pack-objects.c: remove duplicate hash lookup 2021-08-29 23:25:43 -07:00
oid-array.c
oid-array.h
oidmap.c
oidmap.h
oidset.c oidset: make oidset_size() an inline function 2021-09-12 16:14:32 -07:00
oidset.h oidset: make oidset_size() an inline function 2021-09-12 16:14:32 -07:00
oidtree.c oidtree: avoid unaligned access to crit-bit tree 2021-08-15 13:13:50 -07:00
oidtree.h
pack-bitmap-write.c pack-bitmap: read multi-pack bitmaps 2021-09-01 13:56:43 -07:00
pack-bitmap.c pack-bitmap: drop bitmap_index argument from try_partial_reuse() 2021-09-09 17:32:40 -07:00
pack-bitmap.h pack-bitmap: drop repository argument from prepare_midx_bitmap_git() 2021-09-09 17:32:37 -07:00
pack-check.c
pack-objects.c
pack-objects.h
pack-revindex.c
pack-revindex.h pack-revindex.h: correct the time complexity descriptions 2021-09-15 22:16:25 -07:00
pack-write.c Merge branch 'tb/pack-finalize-ordering' 2021-09-20 15:20:42 -07:00
pack.h pack-write: split up finish_tmp_packfile() function 2021-09-09 18:23:11 -07:00
packfile.c Merge branch 'rs/packfile-bad-object-list-in-oidset' 2021-09-23 13:44:46 -07:00
packfile.h packfile: convert has_packed_and_bad() to object_id 2021-09-12 16:14:32 -07:00
pager.c
parallel-checkout.c
parallel-checkout.h
parse-options-cb.c
parse-options.c parse-options API: remove OPTION_ARGUMENT feature 2021-09-12 23:27:38 -07:00
parse-options.h parse-options API: remove OPTION_ARGUMENT feature 2021-09-12 23:27:38 -07:00
patch-delta.c
patch-ids.c
patch-ids.h
path.c Merge branch 'lh/systemd-timers' 2021-09-20 15:20:40 -07:00
path.h
pathspec.c
pathspec.h
pkt-line.c pkt-line: add stdio packet write functions 2021-09-01 10:20:39 -07:00
pkt-line.h pkt-line: add stdio packet write functions 2021-09-01 10:20:39 -07:00
preload-index.c
pretty.c logmsg_reencode(): warn when iconv() fails 2021-08-27 12:43:22 -07:00
pretty.h
prio-queue.c
prio-queue.h
progress.c
progress.h
promisor-remote.c
promisor-remote.h
prompt.c
prompt.h
protocol-caps.c Merge branch 'ab/serve-cleanup' 2021-09-20 15:20:43 -07:00
protocol-caps.h
protocol.c
protocol.h
prune-packed.c
prune-packed.h
quote.c
quote.h Merge branch 'zh/ref-filter-raw-data' 2021-08-24 15:32:37 -07:00
range-diff.c Merge branch 'rs/range-diff-avoid-segfault-with-I' 2021-09-15 13:15:27 -07:00
range-diff.h
reachable.c
reachable.h
read-cache.c sparse-index: add SPARSE_INDEX_MEMORY_ONLY flag 2021-09-07 22:41:10 -07:00
rebase-interactive.c
rebase-interactive.h
rebase.c
rebase.h
ref-filter.c Merge branch 'zh/ref-filter-raw-data' 2021-08-24 15:32:37 -07:00
ref-filter.h
reflog-walk.c
reflog-walk.h
refs.c refs: turn on GIT_REF_PARANOIA by default 2021-09-27 12:36:45 -07:00
refs.h
refspec.c
refspec.h
remote-curl.c Merge branch 'ab/http-drop-old-curl' 2021-08-24 15:32:36 -07:00
remote.c Merge branch 'cb/remote-ndebug-fix' 2021-09-10 11:46:30 -07:00
remote.h
replace-object.c
replace-object.h
repo-settings.c
repository.c submodule: extract path to submodule gitdir func 2021-09-15 12:59:12 -07:00
repository.h
rerere.c
rerere.h
reset.c
reset.h
resolve-undo.c
resolve-undo.h
revision.c
revision.h
run-command.c Merge branch 'mr/bisect-in-c-4' 2021-09-23 13:44:48 -07:00
run-command.h Merge branch 'mr/bisect-in-c-4' 2021-09-23 13:44:48 -07:00
send-pack.c Merge branch 'jt/push-negotiation-fixes' 2021-08-24 15:32:40 -07:00
send-pack.h
sequencer.c Merge branch 'ds/mergies-with-sparse-index' 2021-09-20 15:20:45 -07:00
sequencer.h sequencer: advise if skipping cherry-picked commit 2021-08-30 16:35:36 -07:00
serve.c
serve.h
server-info.c
setup.c setup: use xopen and xdup in sanitize_stdfds 2021-09-09 17:40:02 -07:00
sh-i18n--envsubst.c
sha1dc_git.c
sha1dc_git.h
shallow.c
shallow.h
shell.c
shortlog.h
sideband.c
sideband.h
sigchain.c
sigchain.h
simple-ipc.h
sparse-index.c Merge branch 'ds/sparse-index-ignored-files' 2021-09-20 15:20:44 -07:00
sparse-index.h sparse-index: add SPARSE_INDEX_MEMORY_ONLY flag 2021-09-07 22:41:10 -07:00
split-index.c
split-index.h
stable-qsort.c
strbuf.c
strbuf.h
streaming.c
streaming.h
string-list.c
string-list.h
strmap.c
strmap.h
strvec.c
strvec.h strvec: use size_t to store nr and alloc 2021-09-12 16:25:23 -07:00
sub-process.c
sub-process.h
submodule-config.c submodule-config: pass repo upon blob config read 2021-09-08 11:48:09 -07:00
submodule-config.h
submodule.c Merge branch 'jt/submodule-name-to-gitdir' 2021-09-23 13:44:49 -07:00
submodule.h Merge branch 'jt/submodule-name-to-gitdir' 2021-09-23 13:44:49 -07:00
symlinks.c
tag.c
tag.h
tar.h
tempfile.c
tempfile.h
thread-utils.c
thread-utils.h
tmp-objdir.c
tmp-objdir.h
trace.c
trace.h
trace2.c
trace2.h
trailer.c
trailer.h
transport-helper.c
transport-internal.h
transport.c Merge branch 'ab/serve-cleanup' 2021-09-20 15:20:43 -07:00
transport.h
tree-diff.c tree-diff: fix leak when not HAVE_ALLOCA_H 2021-09-16 13:43:42 -07:00
tree-walk.c
tree-walk.h
tree.c
tree.h
unicode-width.h
unimplemented.sh
unix-socket.c
unix-socket.h
unix-stream-server.c
unix-stream-server.h
unpack-trees.c Merge branch 'ds/sparse-index-ignored-files' 2021-09-20 15:20:44 -07:00
unpack-trees.h
upload-pack.c Merge branch 'ab/serve-cleanup' 2021-09-20 15:20:43 -07:00
upload-pack.h
url.c
url.h
urlmatch.c
urlmatch.h
usage.c
userdiff.c Merge branch 'uk/userdiff-php-enum' 2021-09-10 11:46:27 -07:00
userdiff.h
utf8.c
utf8.h
varint.c
varint.h
version.c
version.h
versioncmp.c
walker.c
walker.h
wildmatch.c
wildmatch.h
worktree.c
worktree.h
wrap-for-bin.sh
wrapper.c xopen: explicitly report creation failures 2021-08-25 14:39:06 -07:00
write-or-die.c pkt-line: add stdio packet write functions 2021-09-01 10:20:39 -07:00
ws.c
wt-status.c advice: remove read uses of most global `advice_` variables 2021-08-25 12:07:52 -07:00
wt-status.h
xdiff-interface.c
xdiff-interface.h
zlib.c

README.md

Build status

Git - fast, scalable, distributed revision control system

Git is a fast, scalable, distributed revision control system with an unusually rich command set that provides both high-level operations and full access to internals.

Git is an Open Source project covered by the GNU General Public License version 2 (some parts of it are under different licenses, compatible with the GPLv2). It was originally written by Linus Torvalds with help of a group of hackers around the net.

Please read the file INSTALL for installation instructions.

Many Git online resources are accessible from https://git-scm.com/ including full documentation and Git related tools.

See Documentation/gittutorial.txt to get started, then see Documentation/giteveryday.txt for a useful minimum set of commands, and Documentation/git-<commandname>.txt for documentation of each command. If git has been correctly installed, then the tutorial can also be read with man gittutorial or git help tutorial, and the documentation of each command with man git-<commandname> or git help <commandname>.

CVS users may also want to read Documentation/gitcvs-migration.txt (man gitcvs-migration or git help cvs-migration if git is installed).

The user discussion and development of Git take place on the Git mailing list -- everyone is welcome to post bug reports, feature requests, comments and patches to git@vger.kernel.org (read Documentation/SubmittingPatches for instructions on patch submission). To subscribe to the list, send an email with just "subscribe git" in the body to majordomo@vger.kernel.org. The mailing list archives are available at https://lore.kernel.org/git/, http://marc.info/?l=git and other archival sites.

Issues which are security relevant should be disclosed privately to the Git Security mailing list git-security@googlegroups.com.

The maintainer frequently sends the "What's cooking" reports that list the current status of various development topics to the mailing list. The discussion following them give a good reference for project status, development direction and remaining tasks.

The name "git" was given by Linus Torvalds when he wrote the very first version. He described the tool as "the stupid content tracker" and the name as (depending on your mood):

  • random three-letter combination that is pronounceable, and not actually used by any common UNIX command. The fact that it is a mispronunciation of "get" may or may not be relevant.
  • stupid. contemptible and despicable. simple. Take your pick from the dictionary of slang.
  • "global information tracker": you're in a good mood, and it actually works for you. Angels sing, and a light suddenly fills the room.
  • "goddamn idiotic truckload of sh*t": when it breaks