changegroup: avoid creating empty changegroup part
Previously this check happened in the changegroup code itself. Since its
refactor, this logic needs to move out to callers that care about it, such as
this one. Otherwise we get empty bundle devel-warnings in certain extensions.
Differential Revision: https://phab.mercurial-scm.org/D690
#ifndef _HG_BDIFF_H_
#define _HG_BDIFF_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