dirstate: clean up when restoring identical backups
When a dirstate backup is restored, it is possible that no actual changes to
the dirstate have been made. In this case, the backup is still a hardlink
to the original dirstate.
Unfortunately, `os.rename` silently fails (nothing happens, and no error
occurs) when `src` and `dst` are hardlinks to the same file. As a result,
the backup is left lying around. Over time, these files accumulate.
When restoring dirstate backups, check if the backup and the dirstate are
the same file, and if so, just delete the backup.
Differential Revision: https://phab.mercurial-scm.org/D1201
#ifndef _HG_MPATCH_H_
#define _HG_MPATCH_H_
#define MPATCH_ERR_NO_MEM -3
#define MPATCH_ERR_CANNOT_BE_DECODED -2
#define MPATCH_ERR_INVALID_PATCH -1
struct mpatch_frag {
int start, end, len;
const char *data;
};
struct mpatch_flist {
struct mpatch_frag *base, *head, *tail;
};
int mpatch_decode(const char *bin, ssize_t len, struct mpatch_flist **res);
ssize_t mpatch_calcsize(ssize_t len, struct mpatch_flist *l);
void mpatch_lfree(struct mpatch_flist *a);
int mpatch_apply(char *buf, const char *orig, ssize_t len,
struct mpatch_flist *l);
struct mpatch_flist *
mpatch_fold(void *bins, struct mpatch_flist *(*get_next_item)(void *, ssize_t),
ssize_t start, ssize_t end);
#endif