git/apply.h
Jerry Zhang 324eb77ee7 git-apply: add --allow-empty flag
Some users or scripts will pipe "git diff"
output to "git apply" when replaying diffs
or commits. In these cases, they will rely
on the return value of "git apply" to know
whether the diff was applied successfully.

However, for empty commits, "git apply" will
fail. This complicates scripts since they
have to either buffer the diff and check
its length, or run diff again with "exit-code",
essentially doing the diff twice.

Add the "--allow-empty" flag to "git apply"
which allows it to handle both empty diffs
and empty commits created by "git format-patch
--always" by doing nothing and returning 0.

Add tests for both with and without --allow-empty.

Signed-off-by: Jerry Zhang <jerry@skydio.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-13 14:30:25 -08:00

192 lines
5.3 KiB
C

#ifndef APPLY_H
#define APPLY_H
#include "hash.h"
#include "lockfile.h"
#include "string-list.h"
struct repository;
enum apply_ws_error_action {
nowarn_ws_error,
warn_on_ws_error,
die_on_ws_error,
correct_ws_error
};
enum apply_ws_ignore {
ignore_ws_none,
ignore_ws_change
};
enum apply_verbosity {
verbosity_silent = -1,
verbosity_normal = 0,
verbosity_verbose = 1
};
/*
* We need to keep track of how symlinks in the preimage are
* manipulated by the patches. A patch to add a/b/c where a/b
* is a symlink should not be allowed to affect the directory
* the symlink points at, but if the same patch removes a/b,
* it is perfectly fine, as the patch removes a/b to make room
* to create a directory a/b so that a/b/c can be created.
*
* See also "struct string_list symlink_changes" in "struct
* apply_state".
*/
#define APPLY_SYMLINK_GOES_AWAY 01
#define APPLY_SYMLINK_IN_RESULT 02
struct apply_state {
const char *prefix;
/* Lock file */
struct lock_file lock_file;
/* These control what gets looked at and modified */
int apply; /* this is not a dry-run */
int cached; /* apply to the index only */
int check; /* preimage must match working tree, don't actually apply */
int check_index; /* preimage must match the indexed version */
int update_index; /* check_index && apply */
int ita_only; /* add intent-to-add entries to the index */
/* These control cosmetic aspect of the output */
int diffstat; /* just show a diffstat, and don't actually apply */
int numstat; /* just show a numeric diffstat, and don't actually apply */
int summary; /* just report creation, deletion, etc, and don't actually apply */
/* These boolean parameters control how the apply is done */
int allow_overlap;
int apply_in_reverse;
int apply_with_reject;
int no_add;
int threeway;
int unidiff_zero;
int unsafe_paths;
int allow_empty;
/* Other non boolean parameters */
struct repository *repo;
const char *index_file;
enum apply_verbosity apply_verbosity;
const char *fake_ancestor;
const char *patch_input_file;
int line_termination;
struct strbuf root;
int p_value;
int p_value_known;
unsigned int p_context;
/* Exclude and include path parameters */
struct string_list limit_by_name;
int has_include;
/* Various "current state" */
int linenr; /* current line number */
struct string_list symlink_changes; /* we have to track symlinks */
/*
* For "diff-stat" like behaviour, we keep track of the biggest change
* we've seen, and the longest filename. That allows us to do simple
* scaling.
*/
int max_change;
int max_len;
/*
* Records filenames that have been touched, in order to handle
* the case where more than one patches touch the same file.
*/
struct string_list fn_table;
/*
* This is to save reporting routines before using
* set_error_routine() or set_warn_routine() to install muting
* routines when in verbosity_silent mode.
*/
void (*saved_error_routine)(const char *err, va_list params);
void (*saved_warn_routine)(const char *warn, va_list params);
/* These control whitespace errors */
enum apply_ws_error_action ws_error_action;
enum apply_ws_ignore ws_ignore_action;
const char *whitespace_option;
int whitespace_error;
int squelch_whitespace_errors;
int applied_after_fixing_ws;
};
/*
* This represents a "patch" to a file, both metainfo changes
* such as creation/deletion, filemode and content changes represented
* as a series of fragments.
*/
struct patch {
char *new_name, *old_name, *def_name;
unsigned int old_mode, new_mode;
int is_new, is_delete; /* -1 = unknown, 0 = false, 1 = true */
int rejected;
unsigned ws_rule;
int lines_added, lines_deleted;
int score;
int extension_linenr; /* first line specifying delete/new/rename/copy */
unsigned int is_toplevel_relative:1;
unsigned int inaccurate_eof:1;
unsigned int is_binary:1;
unsigned int is_copy:1;
unsigned int is_rename:1;
unsigned int recount:1;
unsigned int conflicted_threeway:1;
unsigned int direct_to_threeway:1;
unsigned int crlf_in_old:1;
struct fragment *fragments;
char *result;
size_t resultsize;
char old_oid_prefix[GIT_MAX_HEXSZ + 1];
char new_oid_prefix[GIT_MAX_HEXSZ + 1];
struct patch *next;
/* three-way fallback result */
struct object_id threeway_stage[3];
};
int apply_parse_options(int argc, const char **argv,
struct apply_state *state,
int *force_apply, int *options,
const char * const *apply_usage);
int init_apply_state(struct apply_state *state,
struct repository *repo,
const char *prefix);
void clear_apply_state(struct apply_state *state);
int check_apply_state(struct apply_state *state, int force_apply);
/*
* Parse a git diff header, starting at line. Fills the relevant
* metadata information in 'struct patch'.
*
* Returns -1 on failure, the length of the parsed header otherwise.
*/
int parse_git_diff_header(struct strbuf *root,
int *linenr,
int p_value,
const char *line,
int len,
unsigned int size,
struct patch *patch);
/*
* Some aspects of the apply behavior are controlled by the following
* bits in the "options" parameter passed to apply_all_patches().
*/
#define APPLY_OPT_INACCURATE_EOF (1<<0) /* accept inaccurate eof */
#define APPLY_OPT_RECOUNT (1<<1) /* accept inaccurate line count */
int apply_all_patches(struct apply_state *state,
int argc, const char **argv,
int options);
#endif