bookmarks: avoid traceback when two pushes race to delete the same bookmark `hg push -f -B remote-only-bookmark` can raise server-side in `bookmarks._del` (specifically in `self._refmap.pop(mark)`), if the remote-only bookmark got deleted concurrently. Fix this by simply not deleting the non-existent bookmark in that case. For avoidance of doubt, refusing to delete a bookmark that doesn't exist when the push starts is taking care of elsewhere; no change of behavior there. Differential Revision: https://phab.mercurial-scm.org/D8124

#ifndef _HG_BDIFF_H_
#define _HG_BDIFF_H_

#include "compat.h"

struct bdiff_line {
	int hash, n, e;
	ssize_t len;
	const char *l;
};

struct bdiff_hunk;
struct bdiff_hunk {
	int a1, a2, b1, b2;
	struct bdiff_hunk *next;
};

int bdiff_splitlines(const char *a, ssize_t len, struct bdiff_line **lr);
int bdiff_diff(struct bdiff_line *a, int an, struct bdiff_line *b, int bn,
               struct bdiff_hunk *base);
void bdiff_freehunks(struct bdiff_hunk *l);

#endif