Use the BOTTOM flag to define relevance for pruning. Relevant commits
are those that are !UNINTERESTING or BOTTOM, and this allows us to
identify irrelevant side branches (UNINTERESTING && !BOTTOM).
If a merge has relevant parents, and it is TREESAME to them, then do not
let irrelevant parents cause the merge to be treated as !TREESAME.
When considering simplification, don't always include all merges -
merges with exactly one relevant parent can be simplified, if TREESAME
according to the above rule.
These two changes greatly increase simplification in limited, pruned
revision lists.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
History simplification previously always treated merges as TREESAME
if they were TREESAME to any parent.
While this was consistent with the default behaviour, this could be
extremely unhelpful when searching detailed history, and could not be
overridden. For example, if a merge had ignored a change, as if by "-s
ours", then:
git log -m -p --full-history -Schange file
would successfully locate "change"'s addition but would not locate the
merge that resolved against it.
Futher, simplify_merges could drop the actual parent that a commit
was TREESAME to, leaving it as a normal commit marked TREESAME that
isn't actually TREESAME to its remaining parent.
Now redefine a commit's TREESAME flag to be true only if a commit is
TREESAME to _all_ of its parents. This doesn't affect either the default
simplify_history behaviour (because partially TREESAME merges are turned
into normal commits), or full-history with parent rewriting (because all
merges are output). But it does affect other modes. The clearest
difference is that --full-history will show more merges - sufficient to
ensure that -m -p --full-history log searches can really explain every
change to the file, including those changes' ultimate fate in merges.
Also modify simplify_merges to recalculate TREESAME after removing
a parent. This is achieved by storing per-parent TREESAME flags on the
initial scan, so the combined flag can be easily recomputed.
This fixes some t6111 failures, but creates a couple of new ones -
we are now showing some merges that don't need to be shown.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
In preparation for upcoming TREESAME work, check the result for G.t,
which is dropped in "-s ours" merge L. The default rev-list is empty, as
expected - it follows the first parent path where it never existed.
Unfortunately, --ancestry-path is also empty. Merges H J and L are all
TREESAME to 1 parent, so are treated as TREESAME and not shown. This is
clearly undesirable in the case of merge L, which dropped our G.t by
taking the non-ancestry-path version. Document this as a known failure,
and expect "H J L", the 3 merges along the path that had to chose G.t
versions.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The documentation assures users that "A...B" is defined as "A B --not
$(git merge-base --all A B)". This wasn't in fact quite true, because
the calculated merge bases were not sent to add_rev_cmdline().
The main effect of this was that although
git rev-list --ancestry-path A B --not $(git merge-base --all A B)
worked, the simpler form
git rev-list --ancestry-path A...B
failed with a "no bottom commits" error.
Other potential users of bottom commits could also be affected by this
problem, if they examine revs->cmdline_info; I came across the issue in
my proposed history traversal refinements series.
So ensure that the calculated merge bases are sent to add_rev_cmdline(),
flagged with new 'whence' enum value REV_CMD_MERGE_BASE.
Signed-off-by: Kevin Bracey <kevin@bracey.fi>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The criss-cross tests kept failing for me because of collisions of 'a'
with 'A' etc. Prefix the lowercase refnames with an extra letter to
disambiguate.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Acked-by: Brad King <brad.king@kitware.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
If the commit specified as the bottom of the commit range has a direct
parent that has another child commit that contributed to the resulting
history, "rev-list --ancestry-path" was confused and listed that side
history as well, due to the command line parser subtlety corrected by the
previous commit.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
The option added by commit ebdc94f3 (revision: --ancestry-path,
2010-04-20) does not work properly in combination with --all, at least
in the case of a criss-cross merge:
b---bc
/ \ /
a X
\ / \
c---cb
There are no descendants of 'cb' in the history. The command
git rev-list --ancestry-path cb..bc
correctly reports no commits. However, the command
git rev-list --ancestry-path --all ^cb
reports 'bc'. Add a test case to t6019-rev-list-ancestry-path
demonstrating this breakage.
Signed-off-by: Brad King <brad.king@kitware.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
When using --ancestry-path together with history simplification (typically
triggered by path limiting), history simplification would get in the way of
--ancestry-path by prematurely removing the parent links between commits on
which the ancestry path calculations are made.
This patch disables this history simplification when --ancestry-path is
enabled. This is similar to what e.g. --full-history already does.
The patch also includes a simple testcase verifying that --ancestry-path
works together with path limiting.
Signed-off-by: Johan Herland <johan@herland.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
"rev-list A..H" computes the set of commits that are ancestors of H, but
excludes the ones that are ancestors of A. This is useful to see what
happened to the history leading to H since A, in the sense that "what does
H have that did not exist in A" (e.g. when you have a choice to update to
H from A).
x---x---A---B---C <-- topic
/ \
x---x---x---o---o---o---o---M---D---E---F---G <-- dev
/ \
x---o---o---o---o---o---o---o---o---o---o---o---N---H <-- master
The result in the above example would be the commits marked with caps
letters (except for A itself, of course), and the ones marked with 'o'.
When you want to find out what commits in H are contaminated with the bug
introduced by A and need fixing, however, you might want to view only the
subset of "A..B" that are actually descendants of A, i.e. excluding the
ones marked with 'o'. Introduce a new option --ancestry-path to compute
this set with "rev-list --ancestry-path A..B".
Note that in practice, you would build a fix immediately on top of A and
"git branch --contains A" will give the names of branches that you would
need to merge the fix into (i.e. topic, dev and master), so this may not
be worth paying the extra cost of postprocessing.
Signed-off-by: Junio C Hamano <gitster@pobox.com>
