The "trivial merge" codepath wants to optimize itself by making an
internal call to the read-tree machinery, but it does not read the index
before doing so, and the codepath is never exercised. Incidentally, this
failure to read the index upfront means that the safety to refuse doing
anything when the index is unmerged does not kick in, either.
These two problem are fixed by using read_cache_unmerged() that does read
the index before checking if it is unmerged at the beginning of
cmd_merge().
The primary logic of the merge, however, assumes that the process never
reads the index in-core, and the call to write_cache_as_tree() it makes
from write_tree_trivial() will always read from the on-disk index that is
prepared the strategy back-ends. This assumption is now broken by the
above fix. To fix this issue, we now call discard_cache() before calling
write_tree_trivial() when it wants to write the on-disk index as a tree.
When multiple strategies are tried, their results are evaluated by reading
the resulting index and inspecting it. The codepath needs to make a call
to read_cache() for each successful strategy, and for that to work, they
need to discard_cache() the one read by the previous round.
Also the "trivial merge" forgot that the current commit is one of the
parents of the resulting commit.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
As a general principle, we should not use "git diff" to validate the
results of what git command that is being tested has done. We would not
know if we are testing the command in question, or locating a bug in the
cute hack of "git diff --no-index".
Rather use test_cmp for that purpose.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
This uses "git-apply --whitespace=strip" to fix whitespace errors that have
crept in to our source files over time. There are a few files that need
to have trailing whitespaces (most notably, test vectors). The results
still passes the test, and build result in Documentation/ area is unchanged.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
We have fairly extensive coverage of read-tree 3-way machinery,
and many Porcelain-ish tests use git-merge front-end tests, but
we did not have good basic test for merge-recursive, which made
it very hard to hack on it.
I used this during the recent work to teach D/F conflicts to
merge-recursive.
Signed-off-by: Junio C Hamano <junkio@cox.net>
