git/Documentation/git-apply.txt
Raymond E. Pasco d064702be3 git-apply.txt: update descriptions of --cached, --index
The blurb for "--cached" says it implies "--index", but in reality
"--cached" and "--index" are distinct modes with different behavior.

Additionally, the descriptions of "--index" and "--cached" are somewhat
unclear about what might be modified, and what "--index" looks for to
determine that the index and working copy "match".

Rewrite the blurbs for both options for clarity and accuracy.

Signed-off-by: Raymond E. Pasco <ray@ameretat.dev>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-08-20 16:34:37 -07:00

285 lines
11 KiB
Text

git-apply(1)
============
NAME
----
git-apply - Apply a patch to files and/or to the index
SYNOPSIS
--------
[verse]
'git apply' [--stat] [--numstat] [--summary] [--check] [--index | --intent-to-add] [--3way]
[--apply] [--no-add] [--build-fake-ancestor=<file>] [-R | --reverse]
[--allow-binary-replacement | --binary] [--reject] [-z]
[-p<n>] [-C<n>] [--inaccurate-eof] [--recount] [--cached]
[--ignore-space-change | --ignore-whitespace]
[--whitespace=(nowarn|warn|fix|error|error-all)]
[--exclude=<path>] [--include=<path>] [--directory=<root>]
[--verbose] [--unsafe-paths] [<patch>...]
DESCRIPTION
-----------
Reads the supplied diff output (i.e. "a patch") and applies it to files.
When running from a subdirectory in a repository, patched paths
outside the directory are ignored.
With the `--index` option the patch is also applied to the index, and
with the `--cached` option the patch is only applied to the index.
Without these options, the command applies the patch only to files,
and does not require them to be in a Git repository.
This command applies the patch but does not create a commit. Use
linkgit:git-am[1] to create commits from patches generated by
linkgit:git-format-patch[1] and/or received by email.
OPTIONS
-------
<patch>...::
The files to read the patch from. '-' can be used to read
from the standard input.
--stat::
Instead of applying the patch, output diffstat for the
input. Turns off "apply".
--numstat::
Similar to `--stat`, but shows the number of added and
deleted lines in decimal notation and the pathname without
abbreviation, to make it more machine friendly. For
binary files, outputs two `-` instead of saying
`0 0`. Turns off "apply".
--summary::
Instead of applying the patch, output a condensed
summary of information obtained from git diff extended
headers, such as creations, renames and mode changes.
Turns off "apply".
--check::
Instead of applying the patch, see if the patch is
applicable to the current working tree and/or the index
file and detects errors. Turns off "apply".
--index::
Apply the patch to both the index and the working tree (or
merely check that it would apply cleanly to both if `--check` is
in effect). Note that `--index` expects index entries and
working tree copies for relevant paths to be identical (their
contents and metadata such as file mode must match), and will
raise an error if they are not, even if the patch would apply
cleanly to both the index and the working tree in isolation.
--cached::
Apply the patch to just the index, without touching the working
tree. If `--check` is in effect, merely check that it would
apply cleanly to the index entry.
--intent-to-add::
When applying the patch only to the working tree, mark new
files to be added to the index later (see `--intent-to-add`
option in linkgit:git-add[1]). This option is ignored unless
running in a Git repository and `--index` is not specified.
Note that `--index` could be implied by other options such
as `--cached` or `--3way`.
-3::
--3way::
When the patch does not apply cleanly, fall back on 3-way merge if
the patch records the identity of blobs it is supposed to apply to,
and we have those blobs available locally, possibly leaving the
conflict markers in the files in the working tree for the user to
resolve. This option implies the `--index` option, and is incompatible
with the `--reject` and the `--cached` options.
--build-fake-ancestor=<file>::
Newer 'git diff' output has embedded 'index information'
for each blob to help identify the original version that
the patch applies to. When this flag is given, and if
the original versions of the blobs are available locally,
builds a temporary index containing those blobs.
+
When a pure mode change is encountered (which has no index information),
the information is read from the current index instead.
-R::
--reverse::
Apply the patch in reverse.
--reject::
For atomicity, 'git apply' by default fails the whole patch and
does not touch the working tree when some of the hunks
do not apply. This option makes it apply
the parts of the patch that are applicable, and leave the
rejected hunks in corresponding *.rej files.
-z::
When `--numstat` has been given, do not munge pathnames,
but use a NUL-terminated machine-readable format.
+
Without this option, pathnames with "unusual" characters are quoted as
explained for the configuration variable `core.quotePath` (see
linkgit:git-config[1]).
-p<n>::
Remove <n> leading path components (separated by slashes) from
traditional diff paths. E.g., with `-p2`, a patch against
`a/dir/file` will be applied directly to `file`. The default is
1.
-C<n>::
Ensure at least <n> lines of surrounding context match before
and after each change. When fewer lines of surrounding
context exist they all must match. By default no context is
ever ignored.
--unidiff-zero::
By default, 'git apply' expects that the patch being
applied is a unified diff with at least one line of context.
This provides good safety measures, but breaks down when
applying a diff generated with `--unified=0`. To bypass these
checks use `--unidiff-zero`.
+
Note, for the reasons stated above usage of context-free patches is
discouraged.
--apply::
If you use any of the options marked "Turns off
'apply'" above, 'git apply' reads and outputs the
requested information without actually applying the
patch. Give this flag after those flags to also apply
the patch.
--no-add::
When applying a patch, ignore additions made by the
patch. This can be used to extract the common part between
two files by first running 'diff' on them and applying
the result with this option, which would apply the
deletion part but not the addition part.
--allow-binary-replacement::
--binary::
Historically we did not allow binary patch applied
without an explicit permission from the user, and this
flag was the way to do so. Currently we always allow binary
patch application, so this is a no-op.
--exclude=<path-pattern>::
Don't apply changes to files matching the given path pattern. This can
be useful when importing patchsets, where you want to exclude certain
files or directories.
--include=<path-pattern>::
Apply changes to files matching the given path pattern. This can
be useful when importing patchsets, where you want to include certain
files or directories.
+
When `--exclude` and `--include` patterns are used, they are examined in the
order they appear on the command line, and the first match determines if a
patch to each path is used. A patch to a path that does not match any
include/exclude pattern is used by default if there is no include pattern
on the command line, and ignored if there is any include pattern.
--ignore-space-change::
--ignore-whitespace::
When applying a patch, ignore changes in whitespace in context
lines if necessary.
Context lines will preserve their whitespace, and they will not
undergo whitespace fixing regardless of the value of the
`--whitespace` option. New lines will still be fixed, though.
--whitespace=<action>::
When applying a patch, detect a new or modified line that has
whitespace errors. What are considered whitespace errors is
controlled by `core.whitespace` configuration. By default,
trailing whitespaces (including lines that solely consist of
whitespaces) and a space character that is immediately followed
by a tab character inside the initial indent of the line are
considered whitespace errors.
+
By default, the command outputs warning messages but applies the patch.
When `git-apply` is used for statistics and not applying a
patch, it defaults to `nowarn`.
+
You can use different `<action>` values to control this
behavior:
+
* `nowarn` turns off the trailing whitespace warning.
* `warn` outputs warnings for a few such errors, but applies the
patch as-is (default).
* `fix` outputs warnings for a few such errors, and applies the
patch after fixing them (`strip` is a synonym --- the tool
used to consider only trailing whitespace characters as errors, and the
fix involved 'stripping' them, but modern Gits do more).
* `error` outputs warnings for a few such errors, and refuses
to apply the patch.
* `error-all` is similar to `error` but shows all errors.
--inaccurate-eof::
Under certain circumstances, some versions of 'diff' do not correctly
detect a missing new-line at the end of the file. As a result, patches
created by such 'diff' programs do not record incomplete lines
correctly. This option adds support for applying such patches by
working around this bug.
-v::
--verbose::
Report progress to stderr. By default, only a message about the
current patch being applied will be printed. This option will cause
additional information to be reported.
--recount::
Do not trust the line counts in the hunk headers, but infer them
by inspecting the patch (e.g. after editing the patch without
adjusting the hunk headers appropriately).
--directory=<root>::
Prepend <root> to all filenames. If a "-p" argument was also passed,
it is applied before prepending the new root.
+
For example, a patch that talks about updating `a/git-gui.sh` to `b/git-gui.sh`
can be applied to the file in the working tree `modules/git-gui/git-gui.sh` by
running `git apply --directory=modules/git-gui`.
--unsafe-paths::
By default, a patch that affects outside the working area
(either a Git controlled working tree, or the current working
directory when "git apply" is used as a replacement of GNU
patch) is rejected as a mistake (or a mischief).
+
When `git apply` is used as a "better GNU patch", the user can pass
the `--unsafe-paths` option to override this safety check. This option
has no effect when `--index` or `--cached` is in use.
CONFIGURATION
-------------
apply.ignoreWhitespace::
Set to 'change' if you want changes in whitespace to be ignored by default.
Set to one of: no, none, never, false if you want changes in
whitespace to be significant.
apply.whitespace::
When no `--whitespace` flag is given from the command
line, this configuration item is used as the default.
SUBMODULES
----------
If the patch contains any changes to submodules then 'git apply'
treats these changes as follows.
If `--index` is specified (explicitly or implicitly), then the submodule
commits must match the index exactly for the patch to apply. If any
of the submodules are checked-out, then these check-outs are completely
ignored, i.e., they are not required to be up to date or clean and they
are not updated.
If `--index` is not specified, then the submodule commits in the patch
are ignored and only the absence or presence of the corresponding
subdirectory is checked and (if possible) updated.
SEE ALSO
--------
linkgit:git-am[1].
GIT
---
Part of the linkgit:git[1] suite