git-commit-vandalism/commit.h
Ævar Arnfjörð Bjarmason 43d3561805 commit-graph write: don't die if the existing graph is corrupt
When the commit-graph is written we end up calling
parse_commit(). This will in turn invoke code that'll consult the
existing commit-graph about the commit, if the graph is corrupted we
die.

We thus get into a state where a failing "commit-graph verify" can't
be followed-up with a "commit-graph write" if core.commitGraph=true is
set, the graph either needs to be manually removed to proceed, or
core.commitGraph needs to be set to "false".

Change the "commit-graph write" codepath to use a new
parse_commit_no_graph() helper instead of parse_commit() to avoid
this. The latter will call repo_parse_commit_internal() with
use_commit_graph=1 as seen in 177722b344 ("commit: integrate commit
graph with commit parsing", 2018-04-10).

Not using the old graph at all slows down the writing of the new graph
by some small amount, but is a sensible way to prevent an error in the
existing commit-graph from spreading.

Just fixing the current issue would be likely to result in code that's
inadvertently broken in the future. New code might use the
commit-graph at a distance. To detect such cases introduce a
"GIT_TEST_COMMIT_GRAPH_DIE_ON_LOAD" setting used when we do our
corruption tests, and test that a "write/verify" combo works after
every one of our current test cases where we now detect commit-graph
corruption.

Some of the code changes here might be strictly unnecessary, e.g. I
was unable to find cases where the parse_commit() called from
write_graph_chunk_data() didn't exit early due to
"item->object.parsed" being true in
repo_parse_commit_internal() (before the use_commit_graph=1 has any
effect). But let's also convert those cases for good measure, we do
not have exhaustive tests for all possible types of commit-graph
corruption.

This might need to be re-visited if we learn to write the commit-graph
incrementally, but probably not. Hopefully we'll just start by finding
out what commits we have in total, then read the old graph(s) to see
what they cover, and finally write a new graph file with everything
that's missing. In that case the new graph writing code just needs to
continue to use e.g. a parse_commit() that doesn't consult the
existing commit-graphs.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-04-01 12:14:50 +09:00

391 lines
14 KiB
C

#ifndef COMMIT_H
#define COMMIT_H
#include "object.h"
#include "tree.h"
#include "strbuf.h"
#include "decorate.h"
#include "gpg-interface.h"
#include "string-list.h"
#include "pretty.h"
#include "commit-slab.h"
#define COMMIT_NOT_FROM_GRAPH 0xFFFFFFFF
#define GENERATION_NUMBER_INFINITY 0xFFFFFFFF
#define GENERATION_NUMBER_MAX 0x3FFFFFFF
#define GENERATION_NUMBER_ZERO 0
struct commit_list {
struct commit *item;
struct commit_list *next;
};
/*
* The size of this struct matters in full repo walk operations like
* 'git clone' or 'git gc'. Consider using commit-slab to attach data
* to a commit instead of adding new fields here.
*/
struct commit {
struct object object;
timestamp_t date;
struct commit_list *parents;
/*
* If the commit is loaded from the commit-graph file, then this
* member may be NULL. Only access it through get_commit_tree()
* or get_commit_tree_oid().
*/
struct tree *maybe_tree;
uint32_t graph_pos;
uint32_t generation;
unsigned int index;
};
extern int save_commit_buffer;
extern const char *commit_type;
/* While we can decorate any object with a name, it's only used for commits.. */
struct name_decoration {
struct name_decoration *next;
int type;
char name[FLEX_ARRAY];
};
enum decoration_type {
DECORATION_NONE = 0,
DECORATION_REF_LOCAL,
DECORATION_REF_REMOTE,
DECORATION_REF_TAG,
DECORATION_REF_STASH,
DECORATION_REF_HEAD,
DECORATION_GRAFTED,
};
void add_name_decoration(enum decoration_type type, const char *name, struct object *obj);
const struct name_decoration *get_name_decoration(const struct object *obj);
struct commit *lookup_commit(struct repository *r, const struct object_id *oid);
struct commit *lookup_commit_reference(struct repository *r,
const struct object_id *oid);
struct commit *lookup_commit_reference_gently(struct repository *r,
const struct object_id *oid,
int quiet);
struct commit *lookup_commit_reference_by_name(const char *name);
/*
* Look up object named by "oid", dereference tag as necessary,
* get a commit and return it. If "oid" does not dereference to
* a commit, use ref_name to report an error and die.
*/
struct commit *lookup_commit_or_die(const struct object_id *oid, const char *ref_name);
int parse_commit_buffer(struct repository *r, struct commit *item, const void *buffer, unsigned long size, int check_graph);
int repo_parse_commit_internal(struct repository *r, struct commit *item,
int quiet_on_missing, int use_commit_graph);
int repo_parse_commit_gently(struct repository *r,
struct commit *item,
int quiet_on_missing);
static inline int repo_parse_commit(struct repository *r, struct commit *item)
{
return repo_parse_commit_gently(r, item, 0);
}
static inline int parse_commit_no_graph(struct commit *commit)
{
return repo_parse_commit_internal(the_repository, commit, 0, 0);
}
#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
#define parse_commit_internal(item, quiet, use) repo_parse_commit_internal(the_repository, item, quiet, use)
#define parse_commit_gently(item, quiet) repo_parse_commit_gently(the_repository, item, quiet)
#define parse_commit(item) repo_parse_commit(the_repository, item)
#endif
void parse_commit_or_die(struct commit *item);
struct buffer_slab;
struct buffer_slab *allocate_commit_buffer_slab(void);
void free_commit_buffer_slab(struct buffer_slab *bs);
/*
* Associate an object buffer with the commit. The ownership of the
* memory is handed over to the commit, and must be free()-able.
*/
void set_commit_buffer(struct repository *r, struct commit *, void *buffer, unsigned long size);
/*
* Get any cached object buffer associated with the commit. Returns NULL
* if none. The resulting memory should not be freed.
*/
const void *get_cached_commit_buffer(struct repository *, const struct commit *, unsigned long *size);
/*
* Get the commit's object contents, either from cache or by reading the object
* from disk. The resulting memory should not be modified, and must be given
* to unuse_commit_buffer when the caller is done.
*/
const void *repo_get_commit_buffer(struct repository *r,
const struct commit *,
unsigned long *size);
#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
#define get_commit_buffer(c, s) repo_get_commit_buffer(the_repository, c, s)
#endif
/*
* Tell the commit subsytem that we are done with a particular commit buffer.
* The commit and buffer should be the input and return value, respectively,
* from an earlier call to get_commit_buffer. The buffer may or may not be
* freed by this call; callers should not access the memory afterwards.
*/
void repo_unuse_commit_buffer(struct repository *r,
const struct commit *,
const void *buffer);
#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
#define unuse_commit_buffer(c, b) repo_unuse_commit_buffer(the_repository, c, b)
#endif
/*
* Free any cached object buffer associated with the commit.
*/
void free_commit_buffer(struct parsed_object_pool *pool, struct commit *);
struct tree *get_commit_tree(const struct commit *);
struct object_id *get_commit_tree_oid(const struct commit *);
/*
* Release memory related to a commit, including the parent list and
* any cached object buffer.
*/
void release_commit_memory(struct parsed_object_pool *pool, struct commit *c);
/*
* Disassociate any cached object buffer from the commit, but do not free it.
* The buffer (or NULL, if none) is returned.
*/
const void *detach_commit_buffer(struct commit *, unsigned long *sizep);
/* Find beginning and length of commit subject. */
int find_commit_subject(const char *commit_buffer, const char **subject);
struct commit_list *commit_list_insert(struct commit *item,
struct commit_list **list);
struct commit_list **commit_list_append(struct commit *commit,
struct commit_list **next);
unsigned commit_list_count(const struct commit_list *l);
struct commit_list *commit_list_insert_by_date(struct commit *item,
struct commit_list **list);
void commit_list_sort_by_date(struct commit_list **list);
/* Shallow copy of the input list */
struct commit_list *copy_commit_list(struct commit_list *list);
void free_commit_list(struct commit_list *list);
struct rev_info; /* in revision.h, it circularly uses enum cmit_fmt */
extern int has_non_ascii(const char *text);
extern const char *logmsg_reencode(const struct commit *commit,
char **commit_encoding,
const char *output_encoding);
const char *repo_logmsg_reencode(struct repository *r,
const struct commit *commit,
char **commit_encoding,
const char *output_encoding);
#ifndef NO_THE_REPOSITORY_COMPATIBILITY_MACROS
#define logmsg_reencode(c, enc, out) repo_logmsg_reencode(the_repository, c, enc, out)
#endif
extern const char *skip_blank_lines(const char *msg);
/** Removes the first commit from a list sorted by date, and adds all
* of its parents.
**/
struct commit *pop_most_recent_commit(struct commit_list **list,
unsigned int mark);
struct commit *pop_commit(struct commit_list **stack);
void clear_commit_marks(struct commit *commit, unsigned int mark);
void clear_commit_marks_many(int nr, struct commit **commit, unsigned int mark);
enum rev_sort_order {
REV_SORT_IN_GRAPH_ORDER = 0,
REV_SORT_BY_COMMIT_DATE,
REV_SORT_BY_AUTHOR_DATE
};
/*
* Performs an in-place topological sort of list supplied.
*
* invariant of resulting list is:
* a reachable from b => ord(b) < ord(a)
* sort_order further specifies:
* REV_SORT_IN_GRAPH_ORDER: try to show a commit on a single-parent
* chain together.
* REV_SORT_BY_COMMIT_DATE: show eligible commits in committer-date order.
*/
void sort_in_topological_order(struct commit_list **, enum rev_sort_order);
struct commit_graft {
struct object_id oid;
int nr_parent; /* < 0 if shallow commit */
struct object_id parent[FLEX_ARRAY]; /* more */
};
typedef int (*each_commit_graft_fn)(const struct commit_graft *, void *);
struct commit_graft *read_graft_line(struct strbuf *line);
int register_commit_graft(struct repository *r, struct commit_graft *, int);
void prepare_commit_graft(struct repository *r);
struct commit_graft *lookup_commit_graft(struct repository *r, const struct object_id *oid);
struct commit *get_fork_point(const char *refname, struct commit *commit);
/* largest positive number a signed 32-bit integer can contain */
#define INFINITE_DEPTH 0x7fffffff
struct oid_array;
struct ref;
extern int register_shallow(struct repository *r, const struct object_id *oid);
extern int unregister_shallow(const struct object_id *oid);
extern int for_each_commit_graft(each_commit_graft_fn, void *);
extern int is_repository_shallow(struct repository *r);
extern struct commit_list *get_shallow_commits(struct object_array *heads,
int depth, int shallow_flag, int not_shallow_flag);
extern struct commit_list *get_shallow_commits_by_rev_list(
int ac, const char **av, int shallow_flag, int not_shallow_flag);
extern void set_alternate_shallow_file(struct repository *r, const char *path, int override);
extern int write_shallow_commits(struct strbuf *out, int use_pack_protocol,
const struct oid_array *extra);
extern void setup_alternate_shallow(struct lock_file *shallow_lock,
const char **alternate_shallow_file,
const struct oid_array *extra);
extern const char *setup_temporary_shallow(const struct oid_array *extra);
extern void advertise_shallow_grafts(int);
struct shallow_info {
struct oid_array *shallow;
int *ours, nr_ours;
int *theirs, nr_theirs;
struct oid_array *ref;
/* for receive-pack */
uint32_t **used_shallow;
int *need_reachability_test;
int *reachable;
int *shallow_ref;
struct commit **commits;
int nr_commits;
};
extern void prepare_shallow_info(struct shallow_info *, struct oid_array *);
extern void clear_shallow_info(struct shallow_info *);
extern void remove_nonexistent_theirs_shallow(struct shallow_info *);
extern void assign_shallow_commits_to_refs(struct shallow_info *info,
uint32_t **used,
int *ref_status);
extern int delayed_reachability_test(struct shallow_info *si, int c);
#define PRUNE_SHOW_ONLY 1
#define PRUNE_QUICK 2
extern void prune_shallow(unsigned options);
extern struct trace_key trace_shallow;
extern int interactive_add(int argc, const char **argv, const char *prefix, int patch);
extern int run_add_interactive(const char *revision, const char *patch_mode,
const struct pathspec *pathspec);
struct commit_extra_header {
struct commit_extra_header *next;
char *key;
char *value;
size_t len;
};
extern void append_merge_tag_headers(struct commit_list *parents,
struct commit_extra_header ***tail);
extern int commit_tree(const char *msg, size_t msg_len,
const struct object_id *tree,
struct commit_list *parents, struct object_id *ret,
const char *author, const char *sign_commit);
extern int commit_tree_extended(const char *msg, size_t msg_len,
const struct object_id *tree,
struct commit_list *parents,
struct object_id *ret, const char *author,
const char *sign_commit,
struct commit_extra_header *);
extern struct commit_extra_header *read_commit_extra_headers(struct commit *, const char **);
extern void free_commit_extra_headers(struct commit_extra_header *extra);
/*
* Search the commit object contents given by "msg" for the header "key".
* Returns a pointer to the start of the header contents, or NULL. The length
* of the header, up to the first newline, is returned via out_len.
*
* Note that some headers (like mergetag) may be multi-line. It is the caller's
* responsibility to parse further in this case!
*/
extern const char *find_commit_header(const char *msg, const char *key,
size_t *out_len);
/* Find the end of the log message, the right place for a new trailer. */
extern size_t ignore_non_trailer(const char *buf, size_t len);
typedef int (*each_mergetag_fn)(struct commit *commit, struct commit_extra_header *extra,
void *cb_data);
extern int for_each_mergetag(each_mergetag_fn fn, struct commit *commit, void *data);
struct merge_remote_desc {
struct object *obj; /* the named object, could be a tag */
char name[FLEX_ARRAY];
};
extern struct merge_remote_desc *merge_remote_util(struct commit *);
extern void set_merge_remote_desc(struct commit *commit,
const char *name, struct object *obj);
/*
* Given "name" from the command line to merge, find the commit object
* and return it, while storing merge_remote_desc in its ->util field,
* to allow callers to tell if we are told to merge a tag.
*/
struct commit *get_merge_parent(const char *name);
extern int parse_signed_commit(const struct commit *commit,
struct strbuf *message, struct strbuf *signature);
extern int remove_signature(struct strbuf *buf);
/*
* Check the signature of the given commit. The result of the check is stored
* in sig->check_result, 'G' for a good signature, 'U' for a good signature
* from an untrusted signer, 'B' for a bad signature and 'N' for no signature
* at all. This may allocate memory for sig->gpg_output, sig->gpg_status,
* sig->signer and sig->key.
*/
extern int check_commit_signature(const struct commit *commit, struct signature_check *sigc);
/* record author-date for each commit object */
struct author_date_slab;
void record_author_date(struct author_date_slab *author_date,
struct commit *commit);
int compare_commits_by_author_date(const void *a_, const void *b_, void *unused);
/*
* Verify a single commit with check_commit_signature() and die() if it is not
* a good signature. This isn't really suitable for general use, but is a
* helper to implement consistent logic for pull/merge --verify-signatures.
*/
void verify_merge_signature(struct commit *commit, int verbose);
int compare_commits_by_commit_date(const void *a_, const void *b_, void *unused);
int compare_commits_by_gen_then_commit_date(const void *a_, const void *b_, void *unused);
LAST_ARG_MUST_BE_NULL
extern int run_commit_hook(int editor_is_used, const char *index_file, const char *name, ...);
#endif /* COMMIT_H */