mercurial/bdiff.h

diff: extract function for getting possibly re-merged parent to diff against

We'll want to reuse the logic that `hg diff --change` with
`diff.merge` uses. At least `hg log -p` should reuse it. This patch
therefore extracts that code to a function.

Differential Revision: https://phab.mercurial-scm.org/D9957

#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