Commit Graph

65623 Commits

Author SHA1 Message Date
Elijah Newren
e6f8861bd4 setup: introduce startup_info->original_cwd
Removing the current working directory causes all subsequent git
commands run from that directory to get confused and fail with a message
about being unable to read the current working directory:

    $ git status
    fatal: Unable to read current working directory: No such file or directory

Non-git commands likely have similar warnings or even errors, e.g.

    $ bash -c 'echo hello'
    shell-init: error retrieving current directory: getcwd: cannot access parent directories: No such file or directory
    hello

This confuses end users, particularly since the command they get the
error from is not the one that caused the problem; the problem came from
the side-effect of some previous command.

We would like to avoid removing the current working directory of our
parent process; towards this end, introduce a new variable,
startup_info->original_cwd, that tracks the current working directory
that we inherited from our parent process.  For convenience of later
comparisons, we prefer that this new variable store a path relative to
the toplevel working directory (thus much like 'prefix'), except without
the trailing slash.

Subsequent commits will make use of this new variable.

Acked-by: Derrick Stolee <stolee@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:33:12 -08:00
Elijah Newren
8a0d52dfd8 t2501: add various tests for removing the current working directory
Numerous commands will remove directories left empty as a "convenience"
after removing files within them.  That is normally fine, but removing
the current working directory can be rather inconvenient since it can
cause confusion for the user when they run subsequent commands.  For
example, after one git process has removed the current working
directory, git status/log/diff will all abort with the message:

    fatal: Unable to read current working directory: No such file or directory

We also have code paths that, when a file needs to be placed where a
directory is (due to e.g. checkout, merge, reset, whatever), will check
if this is okay and error out if not.  These rules include:
  * all tracked files under that directory are intended to be removed by
    the operation
  * none of the tracked files under that directory have uncommitted
    modification
  * there are no untracked files under that directory
However, if we end up remove the current working directory, we can cause
user confusion when they run subsequent commands, so we would prefer if
there was a fourth rule added to this list: avoid removing the current
working directory.

Since there are several code paths that can result in the current
working directory being removed, add several tests of various different
codepaths.  To make it clearer what the difference between the current
behavior and the behavior at the end of the series, code both of them
into the tests and have the appropriate behavior be selected by a flag.
Subsequent commits will toggle the flag from current to desired
behavior.

Also add a few tests suggested during the review of earlier rounds of
this patch series.

Acked-by: Derrick Stolee <stolee@gmail.com>
Acked-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:33:12 -08:00
Phillip Wood
72962e8b3c diff --color-moved: intern strings
Taking inspiration from xdl_classify_record() assign an id to each
addition and deletion such that lines that match for the current
--color-moved-ws mode share the same unique id. This reduces the
number of hash lookups a little (calculating the ids still involves
one hash lookup per line) but the main benefit is that when growing
blocks of potentially moved lines we can replace string comparisons
which involve chasing a pointer with a simple integer comparison. On a
large diff this commit reduces the time to run 'diff --color-moved' by
37% compared to the previous commit and 31% compared to master, for
'diff --color-moved-ws=allow-indentation-change' the reduction is 28%
compared to the previous commit and 96% compared to master. There is
little change in the performance of 'git log --patch' as the diffs are
smaller.

Test                                                                  HEAD^              HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38(0.33+0.05)    0.38(0.33+0.05)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.88(0.81+0.06)    0.55(0.50+0.04) -37.5%
4002.3: diff --color-moved-ws=allow-indentation-change large change   0.85(0.79+0.06)    0.61(0.54+0.06) -28.2%
4002.4: log --no-color-moved --no-color-moved-ws                      1.16(1.07+0.08)    1.15(1.09+0.05)  -0.9%
4002.5: log --color-moved --no-color-moved-ws                         1.31(1.22+0.08)    1.29(1.19+0.09)  -1.5%
4002.6: log --color-moved-ws=allow-indentation-change                 1.32(1.24+0.08)    1.31(1.18+0.13)  -0.8%

Test                                                                  master             HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38 (0.33+0.05)   0.38(0.33+0.05)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.80 (0.75+0.04)   0.55(0.50+0.04) -31.2%
4002.3: diff --color-moved-ws=allow-indentation-change large change  14.20(14.15+0.05)   0.61(0.54+0.06) -95.7%
4002.4: log --no-color-moved --no-color-moved-ws                      1.15 (1.05+0.09)   1.15(1.09+0.05)  +0.0%
4002.5: log --color-moved --no-color-moved-ws                         1.30 (1.19+0.11)   1.29(1.19+0.09)  -0.8%
4002.6: log --color-moved-ws=allow-indentation-change                 1.70 (1.63+0.06)   1.31(1.18+0.13) -22.9%

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood
b4a5c5c419 diff: use designated initializers for emitted_diff_symbol
This makes it clearer which fields are being explicitly initialized
and will simplify the next commit where we add a new field to the
struct.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood
25e61909e9 diff --color-moved-ws=allow-indentation-change: improve hash lookups
As libxdiff does not have a whitespace flag to ignore the indentation
the code for --color-moved-ws=allow-indentation-change uses
XDF_IGNORE_WHITESPACE and then filters out any hash lookups where
there are non-indentation changes. This filtering is inefficient as
we have to perform another string comparison.

By using the offset data that we have already computed to skip the
indentation we can avoid using XDF_IGNORE_WHITESPACE and safely remove
the extra checks which improves the performance by 11% and paves the
way for the elimination of string comparisons in the next commit.

This change slightly increases the run time of other --color-moved
modes. This could be avoided by using different comparison functions
for the different modes but after the next two commits there is no
measurable benefit in doing so.

There is a change in behavior for lines that begin with a form-feed or
vertical-tab character. Since b46054b374 ("xdiff: use
git-compat-util", 2019-04-11) xdiff does not treat '\f' or '\v' as
whitespace characters. This means that lines starting with those
characters are never considered to be blank and never match a line
that does not start with the same character. After this patch a line
matching "^[\f\v\r]*[ \t]*$" is considered to be blank by
--color-moved-ws=allow-indentation-change and lines beginning
"^[\f\v\r]*[ \t]*" can match another line if the suffixes match. This
changes the output of git show for d18f76dccf ("compat/regex: use the
regex engine from gawk for compat", 2010-08-17) as some lines in the
pre-image before a moved block that contain '\f' are now considered
moved as well as they match a blank line before the moved lines in the
post-image. This commit updates one of the tests to reflect this
change.

Test                                                                  HEAD^             HEAD
--------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38(0.33+0.05)   0.38(0.33+0.05)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.86(0.82+0.04)   0.88(0.84+0.04)  +2.3%
4002.3: diff --color-moved-ws=allow-indentation-change large change   0.97(0.94+0.03)   0.86(0.81+0.05) -11.3%
4002.4: log --no-color-moved --no-color-moved-ws                      1.16(1.07+0.09)   1.16(1.06+0.09)  +0.0%
4002.5: log --color-moved --no-color-moved-ws                         1.32(1.26+0.06)   1.33(1.27+0.05)  +0.8%
4002.6: log --color-moved-ws=allow-indentation-change                 1.35(1.29+0.06)   1.33(1.24+0.08)  -1.5%

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood
eec7f53b31 diff --color-moved: stop clearing potential moved blocks
moved_block_clear() was introduced in 74d156f4a1 ("diff
--color-moved-ws: fix double free crash", 2018-10-04) to free the
memory that was allocated when initializing a potential moved
block. However since 21536d077f ("diff --color-moved-ws: modify
allow-indentation-change", 2018-11-23) initializing a potential moved
block no longer allocates any memory. Up until the last commit we were
relying on moved_block_clear() to set the `match` pointer to NULL when
a block stopped matching, but since that commit we do not clear a
moved block that does not match so it does not make sense to clear
them elsewhere.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood
0e488f1732 diff --color-moved: shrink potential moved blocks as we go
Rather than setting `match` to NULL and then looping over the list of
potential matched blocks for a second time to remove blocks with no
matches just filter out the blocks with no matches as we go.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood
ff046a0066 diff --color-moved: unify moved block growth functions
After the last two commits pmb_advance_or_null() and
pmb_advance_or_null_multi_match() differ only in the comparison they
perform. Lets simplify the code by combining them into a single
function.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:06 -08:00
Phillip Wood
08fba1076f diff --color-moved: call comparison function directly
This change will allow us to easily combine pmb_advance_or_null() and
pmb_advance_or_null_multi_match() in the next commit. Calling
xdiff_compare_lines() directly rather than using a function pointer
from the hash map has little effect on the run time.

Test                                                                  HEAD^             HEAD
-------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38(0.35+0.03)   0.38(0.32+0.06) +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.87(0.83+0.04)   0.87(0.80+0.06) +0.0%
4002.3: diff --color-moved-ws=allow-indentation-change large change   0.97(0.92+0.04)   0.97(0.93+0.04) +0.0%
4002.4: log --no-color-moved --no-color-moved-ws                      1.17(1.06+0.10)   1.16(1.10+0.05) -0.9%
4002.5: log --color-moved --no-color-moved-ws                         1.32(1.24+0.08)   1.31(1.22+0.09) -0.8%
4002.6: log --color-moved-ws=allow-indentation-change                 1.36(1.25+0.10)   1.35(1.25+0.10) -0.7%

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
52d14e166d diff --color-moved-ws=allow-indentation-change: simplify and optimize
If we already have a block of potentially moved lines then as we move
down the diff we need to check if the next line of each potentially
moved line matches the current line of the diff. The implementation of
--color-moved-ws=allow-indentation-change was needlessly performing
this check on all the lines in the diff that matched the current line
rather than just the current line. To exacerbate the problem finding
all the other lines in the diff that match the current line involves a
fuzzy lookup so we were wasting even more time performing a second
comparison to filter out the non-matching lines. Fixing this reduces
time to run
  git diff --color-moved-ws=allow-indentation-change v2.28.0 v2.29.0
by 93% compared to master and simplifies the code.

Test                                                                  HEAD^              HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38 (0.35+0.03)   0.38(0.35+0.03)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.86 (0.80+0.06)   0.87(0.83+0.04)  +1.2%
4002.3: diff --color-moved-ws=allow-indentation-change large change  19.01(18.93+0.06)   0.97(0.92+0.04) -94.9%
4002.4: log --no-color-moved --no-color-moved-ws                      1.16 (1.06+0.09)   1.17(1.06+0.10)  +0.9%
4002.5: log --color-moved --no-color-moved-ws                         1.32 (1.25+0.07)   1.32(1.24+0.08)  +0.0%
4002.6: log --color-moved-ws=allow-indentation-change                 1.71 (1.64+0.06)   1.36(1.25+0.10) -20.5%

Test                                                                  master             HEAD
---------------------------------------------------------------------------------------------------------------
4002.1: diff --no-color-moved --no-color-moved-ws large change        0.38 (0.33+0.05)   0.38(0.35+0.03)  +0.0%
4002.2: diff --color-moved --no-color-moved-ws large change           0.80 (0.75+0.04)   0.87(0.83+0.04)  +8.7%
4002.3: diff --color-moved-ws=allow-indentation-change large change  14.20(14.15+0.05)   0.97(0.92+0.04) -93.2%
4002.4: log --no-color-moved --no-color-moved-ws                      1.15 (1.05+0.09)   1.17(1.06+0.10)  +1.7%
4002.5: log --color-moved --no-color-moved-ws                         1.30 (1.19+0.11)   1.32(1.24+0.08)  +1.5%
4002.6: log --color-moved-ws=allow-indentation-change                 1.70 (1.63+0.06)   1.36(1.25+0.10) -20.0%

Helped-by: Jeff King <peff@peff.net>
Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
76e32d6193 diff: simplify allow-indentation-change delta calculation
Now that we reliably end a block when the sign changes we don't need
the whitespace delta calculation to rely on the sign.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
eb89352504 diff --color-moved: avoid false short line matches and bad zebra coloring
When marking moved lines it is possible for a block of potential
matched lines to extend past a change in sign when there is a sequence
of added lines whose text matches the text of a sequence of deleted
and added lines. Most of the time either `match` will be NULL or
`pmb_advance_or_null()` will fail when the loop encounters a change of
sign but there are corner cases where `match` is non-NULL and
`pmb_advance_or_null()` successfully advances the moved block despite
the change in sign.

One consequence of this is highlighting a short line as moved when it
should not be. For example

-moved line  # Correctly highlighted as moved
+short line  # Wrongly highlighted as moved
 context
+moved line  # Correctly highlighted as moved
+short line
 context
-short line

The other consequence is coloring a moved addition following a moved
deletion in the wrong color. In the example below the first "+moved
line 3" should be highlighted as newMoved not newMovedAlternate.

-moved line 1 # Correctly highlighted as oldMoved
-moved line 2 # Correctly highlighted as oldMovedAlternate
+moved line 3 # Wrongly highlighted as newMovedAlternate
 context      # Everything else is highlighted correctly
+moved line 2
+moved line 3
 context
+moved line 1
-moved line 3

These false matches are more likely when using --color-moved-ws with
the exception of --color-moved-ws=allow-indentation-change which ties
the sign of the current whitespace delta to the sign of the line to
avoid this problem. The fix is to check that the sign of the new line
being matched is the same as the sign of the line that started the
block of potential matches.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
eb315457f6 diff --color-moved=zebra: fix alternate coloring
b0a2ba4776 ("diff --color-moved=zebra: be stricter with color
alternation", 2018-11-23) sought to avoid using the alternate colors
unless there are two adjacent moved blocks of the same
sign. Unfortunately it contains two bugs that prevented it from fixing
the problem properly. Firstly `last_symbol` is reset at the start of
each iteration of the loop losing the symbol of the last line and
secondly when deciding whether to use the alternate color it should be
checking if the current line is the same sign of the last line, not a
different sign. The combination of the two errors means that we still
use the alternate color when we should do but we also use it when we
shouldn't. This is most noticable when using
--color-moved-ws=allow-indentation-change with hunks like

-this line gets indented
+    this line gets indented

where the post image is colored with newMovedAlternate rather than
newMoved. While this does not matter much, the next commit will change
the coloring to be correct in this case, so lets fix the bug here to
make it clear why the output is changing and add a regression test.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
0990658bf8 diff --color-moved: rewind when discarding pmb
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
7dfe427107 diff --color-moved: factor out function
This code is quite heavily indented and having it in its own function
simplifies an upcoming change.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
bea084ba41 diff --color-moved: clear all flags on blocks that are too short
If a block of potentially moved lines is not long enough then the
DIFF_SYMBOL_MOVED_LINE flag is cleared on the matching lines so they
are not marked as moved. To avoid problems when we start rewinding
after an unsuccessful match in a couple of commits time make sure all
the move related flags are cleared, not just DIFF_SYMBOL_MOVED_LINE.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Phillip Wood
f73613ac33 diff --color-moved: add perf tests
Add some tests so we can monitor changes to the performance of the
move detection code. The tests record the performance --color-moved
and --color-moved-ws=allow-indentation-change for a large diff and a
sequence of smaller diffs. The range of commits used for the large
diff can be customized by exporting TEST_REV_A and TEST_REV_B when
running the test.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-09 13:24:05 -08:00
Junio C Hamano
deefc2d9f6 flex-array: simplify compiler-specific workaround
We use "type array[];" syntax for the flex-array member at the end
of a struct under C99 or later, except when we are building with
older SUNPRO_C compilers.  As we find more vendor compilers that
claim to grok C99 but not understand the flex-array syntax, the
existing "If we are using C99, but not with these compilers..."
conditional will keep growing.

Make it more manageable by listing vendor-specific exceptions
earlier, with the expectation that new exceptions will not be
combined into existing ones to make the condition longer, and
instead will be implemented as a new "#elif" in the cascade of
similar to old SUNPRO_C, we can just add a single line

    #elif defined(_MSC_VER)

immediately before "#elif defined(__GNUC__)" to cause us to fallback
to the safer but a bit wasteful version.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-08 17:45:16 -08:00
Neeraj Singh
ecd81dfc79 tmp-objdir: disable ref updates when replacing the primary odb
When creating a subprocess with a temporary ODB, we set the
GIT_QUARANTINE_ENVIRONMENT env var to tell child Git processes not
to update refs, since the tmp-objdir may go away.

Introduce a similar mechanism for in-process temporary ODBs when
we call tmp_objdir_replace_primary_odb. Now both mechanisms set
the disable_ref_updates flag on the odb, which is queried by
the ref_transaction_prepare function.

Peff's test case [1] was invoking ref updates via the cachetextconv
setting. That particular code silently does nothing when a ref
update is forbidden. See the call to notes_cache_put in
fill_textconv where errors are ignored.

[1] https://lore.kernel.org/git/YVOn3hDsb5pnxR53@coredump.intra.peff.net/

Reported-by: Jeff King <peff@peff.net>
Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-08 14:06:46 -08:00
Neeraj Singh
b3cecf49ea tmp-objdir: new API for creating temporary writable databases
The tmp_objdir API provides the ability to create temporary object
directories, but was designed with the goal of having subprocesses
access these object stores, followed by the main process migrating
objects from it to the main object store or just deleting it.  The
subprocesses would view it as their primary datastore and write to it.

Here we add the tmp_objdir_replace_primary_odb function that replaces
the current process's writable "main" object directory with the
specified one. The previous main object directory is restored in either
tmp_objdir_migrate or tmp_objdir_destroy.

For the --remerge-diff usecase, add a new `will_destroy` flag in `struct
object_database` to mark ephemeral object databases that do not require
fsync durability.

Add 'git prune' support for removing temporary object databases, and
make sure that they have a name starting with tmp_ and containing an
operation-specific name.

Based-on-patch-by: Elijah Newren <newren@gmail.com>

Signed-off-by: Neeraj Singh <neerajsi@microsoft.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-08 14:06:36 -08:00
Jeff King
5f46385309 config.mak.dev: specify -std=gnu99 for gcc/clang
The point of DEVELOPER=1 is to turn up the warnings so we can catch
portability or correctness mistakes at the compiler level. But since
modern compilers tend to default to modern standards like gnu17, we
might miss warnings about older standards, even though we expect Git to
build with compilers that use them.

So it's helpful for developer builds to set the -std argument to our
lowest-common denominator. Traditionally this was c89, but since we're
moving to assuming c99 in 7bc341e21b (git-compat-util: add a test
balloon for C99 support, 2021-12-01) that seems like a good spot to
land. And as explained in that commit, we want "gnu99" because we still
want to take advantage of some extensions when they're available.

The new argument kicks in only for clang and gcc (which we know to
support "-std=" and "gnu" standards). And only for compiler versions
which default to a newer standard. That will avoid accidentally
silencing any build problems that non-developers would run into on older
compilers that default to c89.

My digging found that the default switched to gnu11 in gcc 5.1.0.
Clang's documentation is less clear, but has done so since at least
clang-7. So that's what I put in the conditional here. It's OK to err on
the side of not-enabling this for older compilers. Most developers (as
well as CI) are using much more recent versions, so any warnings will
eventually surface.

A concrete example is anonymous unions, which became legal in c11.
Without this patch, "gcc -pedantic" will not complain about them, but
will if we add in "-std=gnu99".

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-08 13:16:44 -08:00
Junio C Hamano
e95566d909 Merge branch 'bc/require-c99' into jk/limit-developers-to-gnu99
* bc/require-c99:
  git-compat-util: add a test balloon for C99 support
2021-12-08 13:16:32 -08:00
Ævar Arnfjörð Bjarmason
17baeaf82d pull, fetch: fix segfault in --set-upstream option
Fix a segfault in the --set-upstream option added in
24bc1a1292 (pull, fetch: add --set-upstream option, 2019-08-19) added
in v2.24.0.

The code added there did not do the same checking we do for "git
branch" itself since 8efb8899cf (branch: segfault fixes and
validation, 2013-02-23), which in turn fixed the same sort of segfault
I'm fixing now in "git branch --set-upstream-to", see
6183d826ba (branch: introduce --set-upstream-to, 2012-08-20).

The warning message I'm adding here is an amalgamation of the error
added for "git branch" in 8efb8899cf, and the error output
install_branch_config() itself emits, i.e. it trims "refs/heads/" from
the name and says "branch X on remote", not "branch refs/heads/X on
remote".

I think it would make more sense to simply die() here, but in the
other checks for --set-upstream added in 24bc1a1292 we issue a
warning() instead. Let's do the same here for consistency for now.

There was an earlier submitted alternate way of fixing this in [1],
due to that patch breaking threading with the original report at [2] I
didn't notice it before authoring this version. I think the more
detailed warning message here is better, and we should also have tests
for this behavior.

The --no-rebase option to "git pull" is needed as of the recently
merged 7d0daf3f12 (Merge branch 'en/pull-conflicting-options',
2021-08-30).

1. https://lore.kernel.org/git/20210706162238.575988-1-clemens@endorphin.org/
2. https://lore.kernel.org/git/CAG6gW_uHhfNiHGQDgGmb1byMqBA7xa8kuH1mP-wAPEe5Tmi2Ew@mail.gmail.com/

Reported-by: Clemens Fruhwirth <clemens@endorphin.org>
Reported-by: Jan Pokorný <poki@fnusa.cz>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 15:19:28 -08:00
Eric Wong
2c68f577fc cbtree: remove broken and unused cb_unlink
cb_unlink is broken once a node is no longer self-referential
due to subsequent insertions.  This is a consequence of an
intrusive implementation and I'm not sure if it's easily fixable
while retaining our cache-friendly intrusive property (I've
tried for several hours in another project).

In any case, we're not using cb_unlink anywhere in our codebase,
just get rid of it to avoid misleading future readers.

Signed-off-by: Eric Wong <e@80x24.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 15:18:35 -08:00
Ævar Arnfjörð Bjarmason
f5c39c3268 config API: use get_error_routine(), not vreportf()
Change the git_die_config() function added in 5a80e97c82 (config: add
`git_die_config()` to the config-set API, 2014-08-07) to use the
public callbacks in the usage.[ch] API instead of the the underlying
vreportf() function.

In preceding commits the rest of the vreportf() users outside of
usage.c was migrated to die_message(), so we can now make it "static".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:25:16 -08:00
Ævar Arnfjörð Bjarmason
24f6e6d626 usage.c + gc: add and use a die_message_errno()
Change the "error: " output when we exit with 128 due to gc.log errors
to use a "fatal: " prefix instead. To do this add a
die_message_errno() a sibling function to the die_errno() added in a
preceding commit.

Before this we'd expect report_last_gc_error() to return -1 from
error_errno() in this case. It already treated a status of 0 and 1
specially. Let's just document that anything that's not 0 or 1 should
be returned.

We could also retain the "ret < 0" behavior here without hardcoding
128 by returning -128, and having the caller do a "return -ret", but I
think this makes more sense, and preserves the path from
die_message*()'s return value to the "return" without hardcoding
"128".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:25:16 -08:00
Ævar Arnfjörð Bjarmason
0faf84d97d gc: return from cmd_gc(), don't call exit()
A minor code cleanup. Let's "return" from cmd_gc() instead of calling
exit(). See 338abb0f04 (builtins + test helpers: use return instead
of exit() in cmd_*, 2021-06-08) for other such cases.

While we're at it add a \n to separate the variable declaration from
the rest of the code in this block. Both of these changes make a
subsequent change smaller and easier to read.

This change isn't really needed for that subsequent change, but now
someone viewing that future behavior change won't need to wonder why
we're either still calling exit() here, or fixing it while we're at
it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:25:16 -08:00
Ævar Arnfjörð Bjarmason
adcd4d4c6f usage.c API users: use die_message() for error() + exit 128
Continue the migration of code that printed a message and exited with
128. In this case the caller used "error()", so we'll be changing the
output from "error: " to "fatal: ". This change is intentional and
desired.

This code is dying, so it should emit "fatal", the only reason it
didn't do so was because before the existence of "die_message()" it
would have needed to craft its own "fatal: " message.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:25:15 -08:00
Ævar Arnfjörð Bjarmason
e081a7c3b7 usage.c API users: use die_message() for "fatal :" + exit 128
Change code that printed its own "fatal: " message and exited with a
status code of 128 to use the die_message() function added in a
preceding commit.

This change also demonstrates why the return value of
die_message_routine() needed to be that of "report_fn". We have
callers such as the run-command.c::child_err_spew() which would like
to replace its error routine with the return value of
"get_die_message_routine()".

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:25:15 -08:00
Ævar Arnfjörð Bjarmason
18568ee8f8 usage.c: add a die_message() routine
We have code in various places that would like to call die(), but
wants to defer the exit(128) it would invoke, e.g. to print an
additional message, or adjust the exit code. Add a die_message()
helper routine to bridge this gap in the API.

Functionally this behaves just like the error() routine, except it'll
print a "fatal: " prefix, and it will return with 128 instead of -1,
this is so that caller can pass the return value to "exit()", instead
of having to hardcode "exit(128)".

Note that as with the other routines the "die_message_builtin" needs
to return "void" and otherwise conform to the "report_fn"
signature.

As we'll see in a subsequent commit callers will want to replace
e.g. their default "die_routine" with a "die_message_routine".

For now we're just adding the routine and making die_builtin() in
usage.c itself use it. In order to do that we need to add a
get_die_message_routine() function, which works like the other
get_*_routine() functions in usage.c. There is no
set_die_message_rotine(), as it hasn't been needed yet. We can add it
if we ever need it.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:25:15 -08:00
Han-Wen Nienhuys
9912391402 t1430: create valid symrefs using test-helper
This still leaves some other direct filesystem access. Currently, the files
backend does not allow invalidly named symrefs. Fixes for this are currently in
the 'seen' branch

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:20 -08:00
Han-Wen Nienhuys
e39ceeb475 t1430: remove refs using test-tool
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:19 -08:00
Han-Wen Nienhuys
3c966c7b4e refs: introduce REF_SKIP_REFNAME_VERIFICATION flag
Use this flag with the test-helper in t1430, to avoid direct writes to the ref
database.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:19 -08:00
Han-Wen Nienhuys
e9706a188f refs: introduce REF_SKIP_OID_VERIFICATION flag
This lets the ref-store test helper write non-existent or unparsable objects
into the ref storage.

Use this to make t1006 and t3800 independent of the files storage backend.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:19 -08:00
Han-Wen Nienhuys
0464d0a134 refs: update comment.
REF_IS_PRUNING is right below this comment, so it clearly does not belong in
this comment. This was apparently introduced in commit 5ac95fee (Nov 5, 2017
"refs: tidy up and adjust visibility of the `ref_update` flags").

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:19 -08:00
Han-Wen Nienhuys
df25a19d72 test-ref-store: plug memory leak in cmd_delete_refs
Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:19 -08:00
Han-Wen Nienhuys
cd2d40fb7f test-ref-store: parse symbolic flag constants
This lets tests use REF_XXXX constants instead of hardcoded integers. The flag
names should be separated by a ','.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:18 -08:00
Han-Wen Nienhuys
93db6eef04 test-ref-store: remove force-create argument for create-reflog
Nobody uses force_create=0, so this flag is unnecessary.

Signed-off-by: Han-Wen Nienhuys <hanwen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 13:15:18 -08:00
Ævar Arnfjörð Bjarmason
eafd6e7e55 object.c: use BUG(...) no die("BUG: ...") in lookup_object_by_type()
Adjust code added in 7463064b28 (object.h: add
lookup_object_by_type() function, 2021-06-22) to use the BUG()
function.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:33:58 -08:00
Ævar Arnfjörð Bjarmason
a78537a0f2 pathspec: use BUG(...) not die("BUG:%s:%d....", <file>, <line>)
Change code that was added in 8f4f8f4579 (guard against new pathspec
magic in pathspec matching code, 2013-07-14) to use the BUG() macro
instead of emitting a "fatal" message with the "__FILE__"-name and
"__LINE__"-numbers.

The original code predated the existence of the BUG() function, which
was added in d8193743e0 (usage.c: add BUG() function, 2017-05-12).

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:31:17 -08:00
Ævar Arnfjörð Bjarmason
46d699f492 strbuf.h: use BUG(...) not die("BUG: ...")
In 7141efab24 (strbuf: clarify assertion in strbuf_setlen(),
2011-04-27) this 'die("BUG: "' invocation was added with the rationale
that strbuf.c had existing users doing the same, but those users were
later changed to use BUG() in 033abf97fc (Replace all die("BUG: ...")
calls by BUG() ones, 2018-05-02). Let's do the same here.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:31:16 -08:00
Ævar Arnfjörð Bjarmason
5867757d88 pack-objects: use BUG(...) not die("BUG: ...")
Change this code added in da93d12b00 (pack-objects: be incredibly
anal about stdio semantics, 2006-04-02) to use BUG() instead.

See 1a07e59c3e (Update messages in preparation for i18n, 2018-07-21)
for when the "BUG: " prefix was added, and [1] for background on the
Solaris behavior that prompted the exhaustive error checking in this
fgets() loop.

1. https://lore.kernel.org/git/824.1144007555@lotus.CS.Berkeley.EDU/

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:31:16 -08:00
Ævar Arnfjörð Bjarmason
368b584315 common-main.c: call exit(), don't return
Change the main() function to call "exit()" instead of ending with a
"return" statement. The "exit()" function is our own wrapper that
calls trace2_cmd_exit_fl() for us, from git-compat-util.h:

	#define exit(code) exit(trace2_cmd_exit_fl(__FILE__, __LINE__, (code)))

That "exit()" wrapper has been in use ever since ee4512ed48 (trace2:
create new combined trace facility, 2019-02-22).

This changes nothing about how we "exit()", as we'd invoke
"trace2_cmd_exit_fl()" in both cases due to the wrapper, this change
makes it easier to reason about this code, as we're now always
obviously relying on our "exit()" wrapper.

There is already code immediately downstream of our "main()" which has
a hard reliance on that, e.g. the various "exit()" calls downstream of
"cmd_main()" in "git.c".

We even had a comment in "t/helper/test-trace2.c" that seemed to be
confused about how the "exit()" wrapper interacted with uses of
"return", even though it was introduced in the same trace2 series in
a15860dca3 (trace2: t/helper/test-trace2, t0210.sh, t0211.sh,
t0212.sh, 2019-02-22), after the aforementioned ee4512ed48. Perhaps
it pre-dated the "exit()" wrapper?

This change makes the "trace2_cmd_exit()" macro orphaned, we now
always use "trace2_cmd_exit_fl()" directly, but let's keep that
simpler example in place. Even if we're unlikely to get another
"main()" other than the one in our "common-main.c", there's some value
in having the API documentation and example discuss a simpler version
that doesn't require an "exit()" wrapper macro.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-07 12:29:57 -08:00
Lessley Dennington
add4c864b6 blame: enable and test the sparse index
Enable the sparse index for the 'git blame' command. The index was already
not expanded with this command, so the most interesting thing to do is to
add tests that verify that 'git blame' behaves correctly when the sparse
index is enabled and that its performance improves. More specifically, these
cases are:

1. The index is not expanded for 'blame' when given paths in the sparse
checkout cone at multiple levels.

2. Performance measurably improves for 'blame' with sparse index when given
paths in the sparse checkout cone at multiple levels.

The `p2000` tests demonstrate a ~60% execution time reduction when running
'blame' for a file two levels deep and and a ~30% execution time reduction
for a file three levels deep.

Test                                         before  after
----------------------------------------------------------------
2000.62: git blame f2/f4/a (full-v3)         0.31    0.32 +3.2%
2000.63: git blame f2/f4/a (full-v4)         0.29    0.31 +6.9%
2000.64: git blame f2/f4/a (sparse-v3)       0.55    0.23 -58.2%
2000.65: git blame f2/f4/a (sparse-v4)       0.57    0.23 -59.6%
2000.66: git blame f2/f4/f3/a (full-v3)      0.77    0.85 +10.4%
2000.67: git blame f2/f4/f3/a (full-v4)      0.78    0.81 +3.8%
2000.68: git blame f2/f4/f3/a (sparse-v3)    1.07    0.72 -32.7%
2000.99: git blame f2/f4/f3/a (sparse-v4)    1.05    0.73 -30.5%

We do not include paths outside the sparse checkout cone because blame
does not support blaming files that are not present in the working
directory. This is true in both sparse and full checkouts.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington
51ba65b5c3 diff: enable and test the sparse index
Enable the sparse index within the 'git diff' command. Its implementation
already safely integrates with the sparse index because it shares code
with the 'git status' and 'git checkout' commands that were already
integrated.  For more details see:

d76723ee53 (status: use sparse-index throughout, 2021-07-14)
1ba5f45132 (checkout: stop expanding sparse indexes, 2021-06-29)

The most interesting thing to do is to add tests that verify that 'git
diff' behaves correctly when the sparse index is enabled. These cases are:

1. The index is not expanded for 'diff' and 'diff --staged'
2. 'diff' and 'diff --staged' behave the same in full checkout, sparse
checkout, and sparse index repositories in the following partially-staged
scenarios (i.e. the index, HEAD, and working directory differ at a given
path):
    1. Path is within sparse-checkout cone
    2. Path is outside sparse-checkout cone
    3. A merge conflict exists for paths outside sparse-checkout cone

The `p2000` tests demonstrate a ~44% execution time reduction for 'git
diff' and a ~86% execution time reduction for 'git diff --staged' using a
sparse index:

Test                                      before  after
-------------------------------------------------------------
2000.30: git diff (full-v3)               0.33    0.34 +3.0%
2000.31: git diff (full-v4)               0.33    0.35 +6.1%
2000.32: git diff (sparse-v3)             0.53    0.31 -41.5%
2000.33: git diff (sparse-v4)             0.54    0.29 -46.3%
2000.34: git diff --cached (full-v3)      0.07    0.07 +0.0%
2000.35: git diff --cached (full-v4)      0.07    0.08 +14.3%
2000.36: git diff --cached (sparse-v3)    0.28    0.04 -85.7%
2000.37: git diff --cached (sparse-v4)    0.23    0.03 -87.0%

Co-authored-by: Derrick Stolee <dstolee@microsoft.com>
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington
338e2a9acc diff: replace --staged with --cached in t1092 tests
Replace uses of the synonym --staged in t1092 tests with --cached (which
is the real and preferred option). This will allow consistency in the new
tests to be added with the upcoming change to enable the sparse index for
diff.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington
44c7e62e51 repo-settings: prepare_repo_settings only in git repos
Check whether git directory exists before adding any repo settings. If it
does not exist, BUG with the message that one cannot add settings for an
uninitialized repository. If it does exist, proceed with adding repo
settings.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:06 -08:00
Lessley Dennington
27a443b820 test-read-cache: set up repo after git directory
Move repo setup to occur after git directory is set up. This will protect
against test failures in the upcoming change to BUG in
prepare_repo_settings if no git directory exists.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:05 -08:00
Lessley Dennington
0803f9c7cd commit-graph: return if there is no git directory
Return early if git directory does not exist. This will protect against
test failures in the upcoming change to BUG in prepare_repo_settings if no
git directory exists.

Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:05 -08:00
Lessley Dennington
e5b17bda8b git: ensure correct git directory setup with -h
Ensure correct git directory setup when -h is passed with commands. This
specifically applies to repos with special help text configuration
variables and to commands run with -h outside a repository. This
will also protect against test failures in the upcoming change to BUG in
prepare_repo_settings if no git directory exists.

Note: this diff is better seen when ignoring whitespace changes.

Co-authored-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Lessley Dennington <lessleydennington@gmail.com>
Reviewed-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-06 09:55:05 -08:00