The desired default behavior for `git_config_set` is to die
whenever an error occurs. Dying is the default for a lot of
internal functions when failures occur and is in this case the
right thing to do for most callers as otherwise we might run into
inconsistent repositories without noticing.

As some code may rely on the actual return values for
`git_config_set` we still require the ability to invoke these
functions without aborting. Rename the existing `git_config_set`
functions to `git_config_set_gently` to keep them available for
those callers.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When calling `git_config_set` to set 'core.precomposeunicode' we
ignore the return value of the function, which may indicate that
we were unable to write the value back to disk. As the function
is only called by init-db we can and should die when an error
occurs.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we start picking a range of revisions we save the replay
options that are required to restore state when interrupting and
later continuing picking the revisions. However, we do not check
the return values of the `git_config_set` functions, which may
lead us to store incomplete information. As this may lead us to
fail when trying to continue the sequence the error can be fatal.

Fix this by dying immediately when we are unable to write back
any replay option.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When creating an empty repository with `git init-db` we do not
check for error codes returned by `git_config_set` functions.
This may cause the user to end up with an inconsistent repository
without any indication for the user.

Fix this problem by dying early with an error message when we are
unable to write the configuration files to disk.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

The clone command does not check for error codes returned by
`git_config_set` functions. This may cause the user to end up
with an inconsistent repository without any indication with what
went wrong.

Fix this problem by dying with an error message when we are
unable to write the configuration files to disk.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When manipulating remotes we try to set various configuration
values without checking if the values were persisted correctly,
possibly leaving the remote in an inconsistent state.

Fix this issue by dying early and notifying the user about the
error.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we add or set new branches (e.g. by `git remote add -f` or
`git remote set-branches`) we do not check for error codes when
writing the branches to the configuration file. When persisting
the configuration failed we are left with a remote that has none
or not all of the branches that should have been set without
notifying the user.

Fix this issue by dying early on configuration error.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When invoking `git-remote --set-url` we do not check the return
value when writing the actual new URL to the configuration file,
pretending to the user that the configuration has been set while
it was in fact not persisted.

Fix this problem by dying early when setting the config fails.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When setting the 'core.worktree' option for a newly cloned
submodule we ignore the return value of `git_config_set_in_file`.
As this leaves the submodule in an inconsistent state, we instead
want to inform the user that something has gone wrong by printing
an error and aborting the program.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When trying to connect a submodule with its corresponding
repository in '.git/modules' we try to set the core.worktree
setting in the submodule, which may fail due to an error
encountered in `git_config_set_in_file`.

The function is used in the git-mv command when trying to move a
submodule to another location. We already die when renaming a
file fails but do not pay attention to the case where updating
the connection between submodule and its repository fails. As
this leaves the repository in an inconsistent state, as well,
abort the program by dying early and presenting the failure to
the user.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When we try to unset upstream configurations we do not check
return codes for the `git_config_set` functions. As those may
indicate that we were unable to unset the respective
configuration we may exit successfully without any error message
while in fact the upstream configuration was not unset.

Fix this by dying with an error message when we cannot unset the
configuration.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

When setting up a new tracking branch fails due to issues with
the configuration file we do not report any errors to the user
and pretend setting the tracking branch succeeded.

Setting up the tracking branch is handled by the
`install_branch_config` function. We do not want to simply die
there as the function is not only invoked when explicitly setting
upstream information with `git branch --set-upstream-to=`, but
also by `git push --set-upstream` and `git clone`. While it is
reasonable to die in the explict first case, we would lose
information in the latter two cases, so we only print the error
message but continue the program as usual.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

A lot of call-sites for the existing family of `git_config_set`
functions do not check for errors that may occur, e.g. when the
configuration file is locked. In many cases we simply want to die
when such a situation arises.

Introduce wrappers that will cause the program to die in those
cases. These wrappers are temporary only to ease the transition
to let `git_config_set` die by default. They will be removed
later on when `git_config_set` itself has been replaced by
`git_config_set_gently`.
Signed-off-by: NPatrick Steinhardt <ps@pks.im>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

* lv/add-doc-working-tree:
  git-add doc: do not say working directory when you mean working tree

Documentation for "git fetch --depth" has been updated for clarity.

* ss/clone-depth-single-doc:
  docs: clarify that --depth for git-fetch works with newly initialized repos
  docs: say "commits" in the --depth option wording for git-clone
  docs: clarify that passing --depth to git-clone implies --single-branch

* sg/t6050-failing-editor-test-fix:
  t6050-replace: make failing editor test more robust

* ew/for-each-ref-doc:
  for-each-ref: document `creatordate` and `creator` fields

Drop a few old "todo" items by deciding that the change one of them
suggests is not such a good idea, and doing the change the other
one suggested to do.

* ss/user-manual:
  user-manual: add addition gitweb information
  user-manual: add section documenting shallow clones
  glossary: define the term shallow clone
  user-manual: remove temporary branch entry from todo list

The underlying machinery used by "ls-files -o" and other commands
have been taught not to create empty submodule ref cache for a
directory that is not a submodule.  This removes a ton of wasted
CPU cycles.

* jk/ref-cache-non-repository-optim:
  resolve_gitlink_ref: ignore non-repository paths
  clean: make is_git_repository a public function

dirname() emulation has been added, as Msys2 lacks it.

* js/dirname-basename:
  mingw: avoid linking to the C library's isalpha()
  t0060: loosen overly strict expectations
  t0060: verify that basename() and dirname() work as expected
  compat/basename.c: provide a dirname() compatibility function
  compat/basename: make basename() conform to POSIX
  Refactor skipping DOS drive prefixes

* tb/complete-word-diff-regex:
  completion: complete "diff --word-diff-regex="

* pw/completion-stash:
  completion: update completion arguments for stash

* pw/completion-show-branch:
  completion: complete show-branch "--date-order"

* jk/completion-rebase:
  completion: add missing git-rebase options

A few options of "git diff" did not work well when the command was
run from a subdirectory.

* nd/diff-with-path-params:
  diff: make -O and --output work in subdirectory
  diff-no-index: do not take a redundant prefix argument

The "split" subcommand of "git subtree" (in contrib/) incorrectly
skipped merges when it shouldn't, which was corrected.

* dw/subtree-split-do-not-drop-merge:
  contrib/subtree: fix "subtree split" skipped-merge bug

* ew/svn-1.9.0-auth:
  git-svn: fix auth parameter handling on SVN 1.9.0+

"git tag" started listing a tag "foo" as "tags/foo" when a branch
named "foo" exists in the same repository; remove this unnecessary
disambiguation, which is a regression introduced in v2.7.0.

* jk/list-tag-2.7-regression:
  tag: do not show ambiguous tag names as "tags/foo"
  t6300: use test_atom for some un-modern tests

The description for SANITY prerequisite the test suite uses has
been clarified both in the comment and in the implementation.

* jk/sanity:
  test-lib: clarify and tighten SANITY

A recent optimization to filter-branch in v2.7.0 introduced a
regression when --prune-empty filter is used, which has been
corrected.

* jk/filter-branch-no-index:
  filter-branch: resolve $commit^{tree} in no-index case

Many codepaths that run "gc --auto" before exiting kept packfiles
mapped and left the file descriptors to them open, which was not
friendly to systems that cannot remove files that are open.  They
now close the packs before doing so.

* js/close-packs-before-gc:
  receive-pack: release pack files before garbage-collecting
  merge: release pack files before garbage-collecting
  am: release pack files before garbage-collecting
  fetch: release pack files before garbage-collecting

"git rebase", unlike all other callers of "gc --auto", did not
ignore the exit code from "gc --auto".

* jk/ok-to-fail-gc-auto-in-rebase:
  rebase: ignore failures from "gc --auto"

Asking gitweb for a nonexistent commit left a warning in the server
log.

Somebody may want to follow this up with a new test, perhaps?
IIRC, we do test that no Perl warnings are given to the server log,
so this should have been caught if our test coverage were good.

* ho/gitweb-squelch-undef-warning:
  gitweb: squelch "uninitialized value" warning

Some codepaths used fopen(3) when opening a fixed path in $GIT_DIR
(e.g. COMMIT_EDITMSG) that is meant to be left after the command is
done.  This however did not work well if the repository is set to
be shared with core.sharedRepository and the umask of the previous
user is tighter.  They have been made to work better by calling
unlink(2) and retrying after fopen(3) fails with EPERM.

* js/fopen-harder:
  Handle more file writes correctly in shared repos
  commit: allow editing the commit message even in shared repos

The ignore mechanism saw a few regressions around untracked file
listing and sparse checkout selection areas in 2.7.0; the change
that is responsible for the regression has been reverted.

* nd/exclusion-regression-fix:
  Revert "dir.c: don't exclude whole dir prematurely if neg pattern may match"

"git reflog" incorrectly assumed that all objects that used to be
at the tip of a ref must be commits, which caused it to segfault.

* dk/reflog-walk-with-non-commit:
  reflog-walk: don't segfault on non-commit sha1's in the reflog

The documentation has been updated to hint the connection between
the '--signoff' option and DCO.

* dw/signoff-doc:
  Expand documentation describing --signoff

A few unportable C construct have been spotted by clang compiler
and have been fixed.

* jk/clang-pedantic:
  bswap: add NO_UNALIGNED_LOADS define
  avoid shifting signed integers 31 bits