This is the bug that just won't die; there always seems to be another
form of it somewhere. See the commit message of 55f39cf755 ("merge:
fix misleading pre-merge check documentation", 2018-06-30) for a more
detailed explanation), but in short:
<quick summary>
builtin/merge.c contains this important requirement for merge
strategies:
...the index must be in sync with the head commit. The strategies are
responsible to ensure this.
This condition is important to enforce because there are two likely
failure cases when the index isn't in sync with the head commit:
* we silently throw away changes the user had staged before the merge
* we accidentally (and silently) include changes in the merge that
were not part of either of the branches/trees being merged
Discarding users' work and mis-merging are both bad outcomes, especially
when done silently, so naturally this rule was stated sternly -- but,
unfortunately totally ignored in practice unless and until actual bugs
were found. But, fear not: the bugs from this were fixed in commit
ee6566e8d7 ("[PATCH] Rewrite read-tree", 2005-09-05)
through a rewrite of read-tree (again, commit 55f39cf755 has a more
detailed explanation of how this affected merge). And it was fixed
again in commit
160252f816 ("git-merge-ours: make sure our index matches HEAD", 2005-11-03)
...and it was fixed again in commit
3ec62ad9ff ("merge-octopus: abort if index does not match HEAD", 2016-04-09)
...and again in commit
65170c07d4 ("merge-recursive: avoid incorporating uncommitted changes in a merge", 2017-12-21)
...and again in commit
eddd1a411d ("merge-recursive: enforce rule that index matches head before merging", 2018-06-30)
...with multiple testcases added to the testsuite that could be
enumerated in even more commits.
Then, finally, in a patch in the same series as the last fix above, the
documentation about this requirement was fixed in commit 55f39cf755
("merge: fix misleading pre-merge check documentation", 2018-06-30), and
we all lived happily ever after...
</quick summary>
Unfortunately, "ever after" apparently denotes a limited time and it
expired today. The merge-recursive rule to enforce that index matches
head was at the beginning of merge_trees() and would only trigger when
opt->call_depth was 0. Since merge_recursive() doesn't call
merge_trees() until after returning from recursing, this meant that the
check wasn't triggered by merge_recursive() until it had first finished
all the intermediate merges to create virtual merge bases. That is a
potentially HUGE amount of computation (and writing of intermediate
merge results into the .git/objects directory) before it errors out and
says, in effect, "Sorry, I can't do any merging because you have some
local changes that would be overwritten."
Trying to enforce that all of merge_trees(), merge_recursive(), and
merge_recursive_generic() checked the index == head condition earlier
resulted in a bunch of broken tests. It turns out that
merge_recursive() has code to drop and reload the cache while recursing
to create intermediate virtual merge bases, but unfortunately that code
runs even when no recursion is necessary. This unconditional dropping
and reloading of the cache masked a few bugs:
* builtin/merge-recursive.c: didn't even bother loading the index.
* builtin/stash.c: feels like a fake 'builtin' because it repeatedly
invokes git subprocesses all over the place, mixed with other
operations. In particular, invoking "git reset" will reset the
index on disk, but the parent process that invoked it won't
automatically have its in-memory index updated.
* t3030-merge-recursive.h: this test has always been broken in that it
didn't make sure to make index match head before running. But, it
didn't care about the index or even the merge result, just the
verbose output while running. While commit eddd1a411d
("merge-recursive: enforce rule that index matches head before
merging", 2018-06-30) should have uncovered this broken test, it
used a test_must_fail wrapper around the merge-recursive call
because it was known that the merge resulted in a rename/rename
conflict. Thus, that fix only made this test fail for a different
reason, and since the index == head check didn't happen until after
coming all the way back out of the recursion, the testcase had
enough information to pass the one check that it did perform.
So, load the index in builtin/merge-recursive.c, reload the in-memory
index in builtin/stash.c, and modify the t3030 testcase to correctly
setup the index and make sure that the test fails in the expected way
(meaning it reports a rename/rename conflict). This makes sure that
all callers actually make the index match head. The next commit will
then enforce the condition that index matches head earlier so this
problem doesn't return in the future.
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"git stash --keep-index" did not work correctly on paths that have
been removed, which has been fixed.
* tg/stash-keep-index-with-removed-paths:
stash: fix handling removed files with --keep-index
git stash push --keep-index is supposed to keep all changes that have
been added to the index, both in the index and on disk.
Currently this doesn't behave correctly when a file is removed from
the index. Instead of keeping it deleted on disk, --keep-index
currently restores the file.
Fix that behaviour by using 'git checkout' in no-overlay mode which
can faithfully restore the index and working tree. This also
simplifies the code.
Note that this will overwrite untracked files if the untracked file
has the same name as a file that has been deleted in the index.
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In the conversion of 'stash show' to C in dc7bd382b1 ("stash: convert
show to builtin", 2019-02-25), 'git stash show <n>', where n is the
index of a stash got broken, if n is not a file or a valid revision by
itself.
'stash show' accepts any flag 'git diff' accepts for changing the
output format. Internally we use 'setup_revisions()' to parse these
command line flags. Currently we pass the whole argv through to
'setup_revisions()', which includes the stash index.
As the stash index is not a valid revision or a file in the working
tree in most cases however, this 'setup_revisions()' call (and thus
the whole command) ends up failing if we use this form of 'git stash
show'.
Instead of passing the whole argv to 'setup_revisions()', only pass
the flags (and the command name) through, while excluding the stash
reference. The stash reference is parsed (and validated) in
'get_stash_info()' already.
This separate parsing also means that we currently do produce the
correct output if the command succeeds.
Reported-by: Mike Hommey <mh@glandium.org>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Code cleanup.
* jk/unused-params-even-more:
parse_opt_ref_sorting: always use with NONEG flag
pretty: drop unused strbuf from parse_padding_placeholder()
pretty: drop unused "type" parameter in needs_rfc2047_encoding()
parse-options: drop unused ctx parameter from show_gitcomp()
fetch_pack(): drop unused parameters
report_path_error(): drop unused prefix parameter
unpack-trees: drop unused error_type parameters
unpack-trees: drop name_entry from traverse_by_cache_tree()
test-date: drop unused "now" parameter from parse_dates()
update-index: drop unused prefix_length parameter from do_reupdate()
log: drop unused "len" from show_tagger()
log: drop unused rev_info from early output
revision: drop some unused "revs" parameters
Further fixes to "git stash" reimplemented in C.
* js/stash-in-c-pathspec-fix:
stash: pass pathspec as pointer
built-in stash: handle :(glob) pathspecs again
legacy stash: fix "rudimentary backport of -q"
"git stash" rewritten in C.
* ps/stash-in-c: (28 commits)
tests: add a special setup where stash.useBuiltin is off
stash: optionally use the scripted version again
stash: add back the original, scripted `git stash`
stash: convert `stash--helper.c` into `stash.c`
stash: replace all `write-tree` child processes with API calls
stash: optimize `get_untracked_files()` and `check_changes()`
stash: convert save to builtin
stash: make push -q quiet
stash: convert push to builtin
stash: convert create to builtin
stash: convert store to builtin
stash: convert show to builtin
stash: convert list to builtin
stash: convert pop to builtin
stash: convert branch to builtin
stash: convert drop and clear to builtin
stash: convert apply to builtin
stash: mention options in `show` synopsis
stash: add tests for `git stash show` config
stash: rename test cases to be more descriptive
...
In the scripted 'git stash show' when no arguments are passed, we just
pass '--stat' to 'git diff'. When any argument is passed to 'stash
show', we no longer pass '--stat' to 'git diff', and pass whatever
flags are passed directly through to 'git diff'.
By default 'git diff' shows the patch output. So when a user uses
'git stash show --patience', they would be shown the diff as expected,
using the patience algorithm. '--patience' in this case only changes
the diff algorithm, but does not cause 'git diff' to show the diff by
itself. The diff is shown because that's the default behaviour of
'git diff'.
In the C version of 'git stash show', we try to emulate that behaviour
using the internal diff API. However we forgot to set up the default
output format, in case it wasn't set by any of the flags that were
passed through. So 'git stash show --patience' in the builtin version
of stash would be completely silent, while it would show the diff in
the scripted version.
The same thing would happen for other flags that only affect the way a
patch is displayed, rather than switching to a different output format
than the default one.
Fix this by setting up the default output format for 'git diff'.
Reported-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Passing the pathspec by value is potentially confusing, as the copy is
only a shallow copy, so save the overhead of the copy, and pass the
pathspec struct as a pointer.
In addition use copy_pathspec to copy the pathspec into
rev.prune_data, so the copy is a proper deep copy, and owned by the
revision API, as that's what the API expects.
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Drop the unused prefix parameter in do_drop_stash.
We also have an unused "prefix" parameter in the 'create_stash'
function, however we leave that in place for symmetry with the other
top-level functions.
Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When passing a list of pathspecs to, say, `git add`, we need to be
careful to use the original form, not the parsed form of the pathspecs.
This makes a difference e.g. when calling
git stash -- ':(glob)**/*.txt'
where the original form includes the `:(glob)` prefix while the parsed
form does not.
However, in the built-in `git stash`, we passed the parsed (i.e.
incorrect) form, and `git add` would fail with the error message:
fatal: pathspec '**/*.txt' did not match any files
at the stage where `git stash` drops the changes from the worktree, even
if `refs/stash` has been actually updated successfully.
This fixes https://github.com/git-for-windows/git/issues/2037
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
Add a GIT_TEST_STASH_USE_BUILTIN=false test mode which is equivalent
to running with stash.useBuiltin=false. This is needed to spot that
we're not introducing any regressions in the legacy stash version
while we're carrying both it and the new built-in version.
This imitates the equivalent treatment for the built-in rebase in
62c23938fa (tests: add a special setup where rebase.useBuiltin is off,
2018-11-14).
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We recently converted the `git stash` command from Unix shell scripts
to builtins.
Let's end users a way out when they discover a bug in the
builtin command: `stash.useBuiltin`.
As the file name `git-stash` is already in use, let's rename the
scripted backend to `git-legacy-stash`.
To make the test suite pass with `stash.useBuiltin=false`, this commit
also backports rudimentary support for `-q` (but only *just* enough
to appease the test suite), and adds a super-ugly hack to force exit
code 129 for `git stash -h`.
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The old shell script `git-stash.sh` was removed and replaced
entirely by `builtin/stash.c`. In order to do that, `create` and
`push` were adapted to work without `stash.sh`. For example, before
this commit, `git stash create` called `git stash--helper create
--message "$*"`. If it called `git stash--helper create "$@"`, then
some of these changes wouldn't have been necessary.
This commit also removes the word `helper` since now stash is
called directly and not by a shell script.
Signed-off-by: Paul-Sebastian Ungureanu <ungureanupaulsebastian@gmail.com>
Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
