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Revision 6aba117d5cf7128e7bc942888263552fe927e13f authored by Elijah Newren on 29 August 2018, 07:06:13 UTC, committed by Junio C Hamano on 30 August 2018, 14:58:59 UTC 
am: avoid directory rename detection when calling recursive merge machinery
 
Let's say you have the following three trees, where Base is from one commit
behind either master or branch:

   Base  : bar_v1, foo/{file1, file2, file3}
   branch: bar_v2, foo/{file1, file2},       goo/file3
   master: bar_v3, foo/{file1, file2, file3}

Using git-am (or am-based rebase) to apply the changes from branch onto
master results in the following tree:

   Result: bar_merged, goo/{file1, file2, file3}

This is not what users want; they did not rename foo/ -> goo/, they only
renamed one file within that directory.  The reason this happens is am
constructs fake trees (via build_fake_ancestor()) of the following form:

   Base_bfa  : bar_v1, foo/file3
   branch_bfa: bar_v2, goo/file3

Combining these two trees with master's tree:

   master: bar_v3, foo/{file1, file2, file3},

You can see that merge_recursive_generic() would see branch_bfa as renaming
foo/ -> goo/, and master as just adding both foo/file1 and foo/file2.  As
such, it ends up with goo/{file1, file2, file3}

The core problem is that am does not have access to the original trees; it
can only construct trees using the blobs involved in the patch.  As such,
it is not safe to perform directory rename detection within am -3.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 5fdddd9
Raw File
oidset.c 
#include "cache.h"
#include "oidset.h"

int oidset_contains(const struct oidset *set, const struct object_id *oid)
{
	if (!set->map.map.tablesize)
		return 0;
	return !!oidmap_get(&set->map, oid);
}

int oidset_insert(struct oidset *set, const struct object_id *oid)
{
	struct oidmap_entry *entry;

	if (!set->map.map.tablesize)
		oidmap_init(&set->map, 0);
	else if (oidset_contains(set, oid))
		return 1;

	entry = xmalloc(sizeof(*entry));
	oidcpy(&entry->oid, oid);

	oidmap_put(&set->map, entry);
	return 0;
}

int oidset_remove(struct oidset *set, const struct object_id *oid)
{
	struct oidmap_entry *entry;

	entry = oidmap_remove(&set->map, oid);
	free(entry);

	return (entry != NULL);
}

void oidset_clear(struct oidset *set)
{
	oidmap_free(&set->map, 1);
}
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