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git/patch-ids.c
Johannes Schindelin 5748693b91 add_commit_patch_id(): avoid allocating memory unnecessarily
It would appear that we allocate (and forget to release) memory if the
patch ID is not even defined.

Reported by the Coverity tool.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 12:18:19 +09:00

115 lines
3.1 KiB
C

#include "cache.h"
#include "diff.h"
#include "commit.h"
#include "sha1-lookup.h"
#include "patch-ids.h"
static int patch_id_defined(struct commit *commit)
{
/* must be 0 or 1 parents */
return !commit->parents || !commit->parents->next;
}
int commit_patch_id(struct commit *commit, struct diff_options *options,
unsigned char *sha1, int diff_header_only)
{
if (!patch_id_defined(commit))
return -1;
if (commit->parents)
diff_tree_sha1(commit->parents->item->object.oid.hash,
commit->object.oid.hash, "", options);
else
diff_root_tree_sha1(commit->object.oid.hash, "", options);
diffcore_std(options);
return diff_flush_patch_id(options, sha1, diff_header_only);
}
/*
* When we cannot load the full patch-id for both commits for whatever
* reason, the function returns -1 (i.e. return error(...)). Despite
* the "cmp" in the name of this function, the caller only cares about
* the return value being zero (a and b are equivalent) or non-zero (a
* and b are different), and returning non-zero would keep both in the
* result, even if they actually were equivalent, in order to err on
* the side of safety. The actual value being negative does not have
* any significance; only that it is non-zero matters.
*/
static int patch_id_cmp(struct patch_id *a,
struct patch_id *b,
struct diff_options *opt)
{
if (is_null_sha1(a->patch_id) &&
commit_patch_id(a->commit, opt, a->patch_id, 0))
return error("Could not get patch ID for %s",
oid_to_hex(&a->commit->object.oid));
if (is_null_sha1(b->patch_id) &&
commit_patch_id(b->commit, opt, b->patch_id, 0))
return error("Could not get patch ID for %s",
oid_to_hex(&b->commit->object.oid));
return hashcmp(a->patch_id, b->patch_id);
}
int init_patch_ids(struct patch_ids *ids)
{
memset(ids, 0, sizeof(*ids));
diff_setup(&ids->diffopts);
ids->diffopts.detect_rename = 0;
DIFF_OPT_SET(&ids->diffopts, RECURSIVE);
diff_setup_done(&ids->diffopts);
hashmap_init(&ids->patches, (hashmap_cmp_fn)patch_id_cmp, 256);
return 0;
}
int free_patch_ids(struct patch_ids *ids)
{
hashmap_free(&ids->patches, 1);
return 0;
}
static int init_patch_id_entry(struct patch_id *patch,
struct commit *commit,
struct patch_ids *ids)
{
unsigned char header_only_patch_id[GIT_MAX_RAWSZ];
patch->commit = commit;
if (commit_patch_id(commit, &ids->diffopts, header_only_patch_id, 1))
return -1;
hashmap_entry_init(patch, sha1hash(header_only_patch_id));
return 0;
}
struct patch_id *has_commit_patch_id(struct commit *commit,
struct patch_ids *ids)
{
struct patch_id patch;
if (!patch_id_defined(commit))
return NULL;
memset(&patch, 0, sizeof(patch));
if (init_patch_id_entry(&patch, commit, ids))
return NULL;
return hashmap_get(&ids->patches, &patch, &ids->diffopts);
}
struct patch_id *add_commit_patch_id(struct commit *commit,
struct patch_ids *ids)
{
struct patch_id *key;
if (!patch_id_defined(commit))
return NULL;
key = xcalloc(1, sizeof(*key));
if (init_patch_id_entry(key, commit, ids)) {
free(key);
return NULL;
}
hashmap_add(&ids->patches, key);
return key;
}