git/builtin
Stefan Beller 77a9745d19 push options: {pre,post}-receive hook learns about push options
The environment variable GIT_PUSH_OPTION_COUNT is set to the number of
push options sent, and GIT_PUSH_OPTION_{0,1,..} is set to the transmitted
option.

The code is not executed as the push options are set to NULL, nor is the
new capability advertised.

There was some discussion back and forth how to present these push options
to the user as there are some ways to do it:

Keep all options in one environment variable
============================================
+ easiest way to implement in Git
- This would make things hard to parse correctly in the hook.

Put the options in files instead,
filenames are in GIT_PUSH_OPTION_FILES
======================================
+ After a discussion about environment variables and shells, we may not
  want to put user data into an environment variable (see [1] for example).
+ We could transmit binaries, i.e. we're not bound to C strings as
  we are when using environment variables to the user.
+ Maybe easier to parse than constructing environment variable names
  GIT_PUSH_OPTION_{0,1,..} yourself
- cleanup of the temporary files is hard to do reliably
- we have race conditions with multiple clients pushing, hence we'd need
  to use mkstemp. That's not too bad, but still.

Use environment variables, but restrict to key/value pairs
==========================================================
(When the user pushes a push option `foo=bar`, we'd
GIT_PUSH_OPTION_foo=bar)
+ very easy to parse for a simple model of push options
- it's not sufficient for more elaborate models, e.g.
  it doesn't allow doubles (e.g. cc=reviewer@email)

Present the options in different environment variables
======================================================
(This is implemented)
* harder to parse as a user, but we have a sample hook for that.
- doesn't allow binary files
+ allows the same option twice, i.e. is not restrictive about
  options, except for binary files.
+ doesn't clutter a remote directory with (possibly stale)
  temporary files

As we first want to focus on getting simple strings to work
reliably, we go with the last option for now. If we want to
do transmission of binaries later, we can just attach a
'side-channel', e.g. "any push option that contains a '\0' is
put into a file instead of the environment variable and we'd
have new GIT_PUSH_OPTION_FILES, GIT_PUSH_OPTION_FILENAME_{0,1,..}
environment variables".

[1] 'Shellshock' https://lwn.net/Articles/614218/

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-14 15:50:17 -07:00
..
add.c add: add --chmod=+x / --chmod=-x options 2016-06-07 17:43:39 -07:00
am.c am: support --patch-format=mboxrd 2016-06-06 11:40:15 -07:00
annotate.c
apply.c Merge branch 'jk/string-list-static-init' 2016-07-06 13:38:08 -07:00
archive.c
bisect--helper.c
blame.c Merge branch 'jk/string-list-static-init' 2016-07-06 13:38:08 -07:00
branch.c Merge branch 'va/i18n-misc-updates' into maint 2016-05-26 13:17:20 -07:00
bundle.c
cat-file.c Merge branch 'jk/cat-file-buffered-batch-all' 2016-05-31 12:40:54 -07:00
check-attr.c give "nbuf" strbuf a more meaningful name 2016-02-01 13:43:02 -08:00
check-ignore.c give "nbuf" strbuf a more meaningful name 2016-02-01 13:43:02 -08:00
check-mailmap.c strbuf: introduce strbuf_getline_{lf,nul}() 2016-01-15 10:12:51 -08:00
check-ref-format.c use xmallocz to avoid size arithmetic 2016-02-22 14:51:09 -08:00
checkout-index.c checkout-index: disallow "--no-stage" option 2016-02-01 13:43:49 -08:00
checkout.c add: add --chmod=+x / --chmod=-x options 2016-06-07 17:43:39 -07:00
clean.c Merge branch 'jk/tighten-alloc' 2016-02-26 13:37:16 -08:00
clone.c Merge branch 'sb/clone-shallow-passthru' 2016-07-06 13:38:13 -07:00
column.c column: read lines with strbuf_getline() 2016-01-15 10:35:07 -08:00
commit-tree.c Merge branch 'jc/commit-tree-ignore-commit-gpgsign' 2016-05-13 13:18:27 -07:00
commit.c Merge branch 'pb/commit-editmsg-path' 2016-07-06 13:38:06 -07:00
config.c Merge branch 'jk/config-get-urlmatch' into maint 2016-04-14 18:57:43 -07:00
count-objects.c
credential.c
describe.c Remove get_object_hash. 2015-11-20 08:02:05 -05:00
diff-files.c diff: run arguments through precompose_argv 2016-05-13 14:35:49 -07:00
diff-index.c diff: run arguments through precompose_argv 2016-05-13 14:35:49 -07:00
diff-tree.c Merge branch 'ar/diff-args-osx-precompose' into maint 2016-06-06 14:27:35 -07:00
diff.c Merge branch 'ar/diff-args-osx-precompose' into maint 2016-06-06 14:27:35 -07:00
fast-export.c convert trivial cases to ALLOC_ARRAY 2016-02-22 14:51:09 -08:00
fetch-pack.c fetch-pack: fix object_id of exact sha1 2016-03-01 11:19:19 -08:00
fetch.c Merge branch 'km/fetch-do-not-free-remote-name' 2016-07-06 13:38:08 -07:00
fmt-merge-msg.c Merge branch 'rs/pop-commit' into maint 2015-12-11 11:14:13 -08:00
for-each-ref.c ref-filter: add option to match literal pattern 2015-09-17 10:02:49 -07:00
fsck.c fsck_head_link(): remove unneeded flag variable 2016-04-10 11:35:33 -07:00
gc.c Merge branch 'dk/gc-idx-wo-pack' into maint 2015-12-04 11:33:08 -08:00
get-tar-commit-id.c usage: do not insist that standard input must come from a file 2015-10-16 15:27:52 -07:00
grep.c Merge branch 'bc/object-id' 2016-05-06 14:45:44 -07:00
hash-object.c Merge branch 'jk/options-cleanup' 2016-02-10 14:20:08 -08:00
help.c builtin/help.c: use warning_errno() 2016-05-09 12:29:08 -07:00
index-pack.c Merge branch 'va/i18n-misc-updates' into maint 2016-05-26 13:17:20 -07:00
init-db.c Merge branch 'jk/check-repository-format' into maint 2016-05-02 14:24:04 -07:00
interpret-trailers.c Merge branch 'jk/parseopt-string-list' into jk/string-list-static-init 2016-06-13 10:37:48 -07:00
log.c Merge branch 'ew/mboxrd-format-am' 2016-07-06 13:38:11 -07:00
ls-files.c Merge branch 'jk/options-cleanup' 2016-02-10 14:20:08 -08:00
ls-remote.c ls-remote: add support for showing symrefs 2016-01-19 10:07:56 -08:00
ls-tree.c convert trivial sprintf / strcpy calls to xsnprintf 2015-09-25 10:18:18 -07:00
mailinfo.c mailinfo: libify 2015-10-21 15:59:34 -07:00
mailsplit.c mailsplit: support unescaping mboxrd messages 2016-06-06 11:14:43 -07:00
merge-base.c convert trivial cases to ALLOC_ARRAY 2016-02-22 14:51:09 -08:00
merge-file.c builtin/merge-file.c: use error_errno() 2016-05-09 12:29:08 -07:00
merge-index.c use sha1_to_hex_r() instead of strcpy 2015-10-05 11:08:05 -07:00
merge-ours.c
merge-recursive.c convert trivial sprintf / strcpy calls to xsnprintf 2015-09-25 10:18:18 -07:00
merge-tree.c struct name_entry: use struct object_id instead of unsigned char sha1[20] 2016-04-25 14:23:42 -07:00
merge.c Merge branch 'en/merge-trivial-fix' 2016-04-25 15:17:15 -07:00
mktag.c usage: do not insist that standard input must come from a file 2015-10-16 15:27:52 -07:00
mktree.c Merge branch 'jk/tighten-alloc' 2016-02-26 13:37:16 -08:00
mv.c Merge branch 'sb/mv-submodule-fix' into HEAD 2016-05-18 14:40:05 -07:00
name-rev.c Merge branch 'js/name-rev-use-oldest-ref' into maint 2016-05-31 14:08:26 -07:00
notes.c Merge branch 'sb/misc-cleanups' into HEAD 2016-05-18 14:40:15 -07:00
pack-objects.c repack: extend --keep-unreachable to loose objects 2016-06-14 13:57:45 -07:00
pack-redundant.c convert trivial cases to ALLOC_ARRAY 2016-02-22 14:51:09 -08:00
pack-refs.c
patch-id.c Merge branch 'rs/patch-id-use-skip-prefix' 2016-06-03 14:38:03 -07:00
prune-packed.c
prune.c Merge branch 'jk/repository-extension' into maint 2015-11-03 15:32:25 -08:00
pull.c pull: warn on --verify-signatures with --rebase 2016-05-20 15:01:00 -07:00
push.c Merge branch 'mm/push-default-warning' 2016-02-26 13:37:25 -08:00
read-tree.c convert trivial sprintf / strcpy calls to xsnprintf 2015-09-25 10:18:18 -07:00
receive-pack.c push options: {pre,post}-receive hook learns about push options 2016-07-14 15:50:17 -07:00
reflog.c struct name_entry: use struct object_id instead of unsigned char sha1[20] 2016-04-25 14:23:42 -07:00
remote-ext.c typofix: assorted typofixes in comments, documentation and messages 2016-05-06 13:16:37 -07:00
remote-fd.c
remote.c Merge branch 'jk/string-list-static-init' 2016-07-06 13:38:08 -07:00
repack.c repack: extend --keep-unreachable to loose objects 2016-06-14 13:57:45 -07:00
replace.c Merge branch 'js/replace-edit-use-editor-configuration' into maint 2016-05-06 14:53:24 -07:00
rerere.c Sync with 2.6.1 2015-10-05 13:20:08 -07:00
reset.c pathspec: rename free_pathspec() to clear_pathspec() 2016-06-02 14:09:22 -07:00
rev-list.c Merge branch 'jk/rev-list-count-with-bitmap' 2016-06-20 11:01:03 -07:00
rev-parse.c Merge branch 'jk/rev-parse-local-env-vars' into maint 2016-04-14 18:57:44 -07:00
revert.c
rm.c Merge branch 'nd/error-errno' 2016-05-17 14:38:28 -07:00
send-pack.c Merge branch 'sk/send-pack-all-fix' into maint 2016-04-29 14:15:57 -07:00
shortlog.c Merge branch 'jk/parseopt-string-list' into jk/string-list-static-init 2016-06-13 10:37:48 -07:00
show-branch.c Merge branch 'rs/show-branch-argv-array' into maint 2015-12-11 11:14:14 -08:00
show-ref.c show-ref: stop using PARSE_OPT_NO_INTERNAL_HELP 2015-11-20 08:02:07 -05:00
stripspace.c stripspace: call U+0020 a "space" instead of a "blank" 2016-01-29 16:02:34 -08:00
submodule--helper.c Merge branch 'sb/submodule-recommend-shallowness' 2016-06-20 11:01:01 -07:00
symbolic-ref.c symbolic-ref: propagate error code from create_symref() 2015-12-21 12:03:03 -08:00
tag.c Merge branch 'st/verify-tag' 2016-04-29 12:59:09 -07:00
unpack-file.c convert trivial sprintf / strcpy calls to xsnprintf 2015-09-25 10:18:18 -07:00
unpack-objects.c Remove get_object_hash. 2015-11-20 08:02:05 -05:00
update-index.c pathspec: rename free_pathspec() to clear_pathspec() 2016-06-02 14:09:22 -07:00
update-ref.c
update-server-info.c
upload-archive.c builtin/upload-archive.c: use error_errno() 2016-05-09 12:29:08 -07:00
var.c
verify-commit.c
verify-pack.c
verify-tag.c verify-tag: move tag verification code to tag.c 2016-04-22 14:06:46 -07:00
worktree.c Merge branch 'nd/worktree-cleanup-post-head-protection' 2016-07-06 13:38:11 -07:00
write-tree.c