git/merge-blobs.c
Junio C Hamano 6044329cf1 Merge branch 'jk/no-diff-emit-common' into maint
"git merge-tree" used to mishandle "both sides added" conflict with
its own "create a fake ancestor file that has the common parts of
what both sides have added and do a 3-way merge" logic; this has
been updated to use the usual "3-way merge with an empty blob as
the fake common ancestor file" approach used in the rest of the
system.

* jk/no-diff-emit-common:
  xdiff: drop XDL_EMIT_COMMON
  merge-tree: drop generate_common strategy
  merge-one-file: use empty blob for add/add base
2016-03-10 11:13:42 -08:00

93 lines
1.9 KiB
C

#include "cache.h"
#include "run-command.h"
#include "xdiff-interface.h"
#include "ll-merge.h"
#include "blob.h"
#include "merge-blobs.h"
static int fill_mmfile_blob(mmfile_t *f, struct blob *obj)
{
void *buf;
unsigned long size;
enum object_type type;
buf = read_sha1_file(obj->object.oid.hash, &type, &size);
if (!buf)
return -1;
if (type != OBJ_BLOB) {
free(buf);
return -1;
}
f->ptr = buf;
f->size = size;
return 0;
}
static void free_mmfile(mmfile_t *f)
{
free(f->ptr);
}
static void *three_way_filemerge(const char *path, mmfile_t *base, mmfile_t *our, mmfile_t *their, unsigned long *size)
{
int merge_status;
mmbuffer_t res;
/*
* This function is only used by cmd_merge_tree, which
* does not respect the merge.conflictstyle option.
* There is no need to worry about a label for the
* common ancestor.
*/
merge_status = ll_merge(&res, path, base, NULL,
our, ".our", their, ".their", NULL);
if (merge_status < 0)
return NULL;
*size = res.size;
return res.ptr;
}
void *merge_blobs(const char *path, struct blob *base, struct blob *our, struct blob *their, unsigned long *size)
{
void *res = NULL;
mmfile_t f1, f2, common;
/*
* Removed in either branch?
*
* NOTE! This depends on the caller having done the
* proper warning about removing a file that got
* modified in the other branch!
*/
if (!our || !their) {
enum object_type type;
if (base)
return NULL;
if (!our)
our = their;
return read_sha1_file(our->object.oid.hash, &type, size);
}
if (fill_mmfile_blob(&f1, our) < 0)
goto out_no_mmfile;
if (fill_mmfile_blob(&f2, their) < 0)
goto out_free_f1;
if (base) {
if (fill_mmfile_blob(&common, base) < 0)
goto out_free_f2_f1;
} else {
common.ptr = xstrdup("");
common.size = 0;
}
res = three_way_filemerge(path, &common, &f1, &f2, size);
free_mmfile(&common);
out_free_f2_f1:
free_mmfile(&f2);
out_free_f1:
free_mmfile(&f1);
out_no_mmfile:
return res;
}