diff options
| -rw-r--r-- | Documentation/rev-list-options.txt | 34 | ||||
| -rw-r--r-- | revision.c | 26 | ||||
| -rwxr-xr-x | t/t6012-rev-list-simplify.sh | 2 |
3 files changed, 47 insertions, 15 deletions
diff --git a/Documentation/rev-list-options.txt b/Documentation/rev-list-options.txt index f41e86545b..b462f17f62 100644 --- a/Documentation/rev-list-options.txt +++ b/Documentation/rev-list-options.txt @@ -342,13 +342,13 @@ In the following, we will always refer to the same example history to illustrate the differences between simplification settings. We assume that you are filtering for a file `foo` in this commit graph: ----------------------------------------------------------------------- - .-A---M---N---O---P - / / / / / - I B C D E - \ / / / / - `-------------' + .-A---M---N---O---P---Q + / / / / / / + I B C D E Y + \ / / / / / + `-------------' X ----------------------------------------------------------------------- -The horizontal line of history A---P is taken to be the first parent of +The horizontal line of history A---Q is taken to be the first parent of each merge. The commits are: * `I` is the initial commit, in which `foo` exists with contents @@ -369,6 +369,10 @@ each merge. The commits are: * `E` changes `quux` to "xyzzy", and its merge `P` combines the strings to "quux xyzzy". `P` is TREESAME to `O`, but not to `E`. +* `X` is an indpendent root commit that added a new file `side`, and `Y` + modified it. `Y` is TREESAME to `X`. Its merge `Q` added `side` to `P`, and + `Q` is TREESAME to `P`, but not to `Y`. + 'rev-list' walks backwards through history, including or excluding commits based on whether '\--full-history' and/or parent rewriting (via '\--parents' or '\--children') are used. The following settings @@ -409,7 +413,7 @@ parent lines. the example, we get + ----------------------------------------------------------------------- - I A B N D O P + I A B N D O P Q ----------------------------------------------------------------------- + `M` was excluded because it is TREESAME to both parents. `E`, @@ -430,7 +434,7 @@ Along each parent, prune away commits that are not included themselves. This results in + ----------------------------------------------------------------------- - .-A---M---N---O---P + .-A---M---N---O---P---Q / / / / / I B / D / \ / / / / @@ -440,7 +444,7 @@ themselves. This results in Compare to '\--full-history' without rewriting above. Note that `E` was pruned away because it is TREESAME, but the parent list of P was rewritten to contain `E`'s parent `I`. The same happened for `C` and -`N`. +`N`, and `X`, `Y` and `Q`. In addition to the above settings, you can change whether TREESAME affects inclusion: @@ -470,9 +474,9 @@ history according to the following rules: * Set `C'` to `C`. + * Replace each parent `P` of `C'` with its simplification `P'`. In - the process, drop parents that are ancestors of other parents, and - remove duplicates, but take care to never drop all parents that - we are TREESAME to. + the process, drop parents that are ancestors of other parents or that are + root commits TREESAME to an empty tree, and remove duplicates, but take care + to never drop all parents that we are TREESAME to. + * If after this parent rewriting, `C'` is a root or merge commit (has zero or >1 parents), a boundary commit, or !TREESAME, it remains. @@ -490,7 +494,7 @@ The effect of this is best shown by way of comparing to `---------' ----------------------------------------------------------------------- + -Note the major differences in `N` and `P` over '--full-history': +Note the major differences in `N`, `P` and `Q` over '--full-history': + -- * `N`'s parent list had `I` removed, because it is an ancestor of the @@ -498,6 +502,10 @@ Note the major differences in `N` and `P` over '--full-history': + * `P`'s parent list similarly had `I` removed. `P` was then removed completely, because it had one parent and is TREESAME. ++ +* `Q`'s parent list had `Y` simplified to `X`. `X` was then removed, because it + was a TREESAME root. `Q` was then removed completely, because it had one + parent and is TREESAME. -- Finally, there is a fifth simplification mode available: diff --git a/revision.c b/revision.c index 62f399c22f..4f7446c359 100644 --- a/revision.c +++ b/revision.c @@ -2136,6 +2136,22 @@ static int mark_redundant_parents(struct rev_info *revs, struct commit *commit) return marked; } +static int mark_treesame_root_parents(struct rev_info *revs, struct commit *commit) +{ + struct commit_list *p; + int marked = 0; + + for (p = commit->parents; p; p = p->next) { + struct commit *parent = p->item; + if (!parent->parents && (parent->object.flags & TREESAME)) { + parent->object.flags |= TMP_MARK; + marked++; + } + } + + return marked; +} + /* * Awkward naming - this means one parent we are TREESAME to. * cf mark_treesame_root_parents: root parents that are TREESAME (to an @@ -2301,10 +2317,18 @@ static struct commit_list **simplify_one(struct rev_info *revs, struct commit *c * / / o: a commit that touches the paths; * ---o----' * - * Detect and simplify this case. + * Further, a merge of an independent branch that doesn't + * touch the path will reduce to a treesame root parent: + * + * ----o----X X: the commit we are looking at; + * / o: a commit that touches the paths; + * r r: a root commit not touching the paths + * + * Detect and simplify both cases. */ if (1 < cnt) { int marked = mark_redundant_parents(revs, commit); + marked += mark_treesame_root_parents(revs, commit); if (marked) marked -= leave_one_treesame_to_parent(revs, commit); if (marked) diff --git a/t/t6012-rev-list-simplify.sh b/t/t6012-rev-list-simplify.sh index 4e55872b1d..57ce2395d6 100755 --- a/t/t6012-rev-list-simplify.sh +++ b/t/t6012-rev-list-simplify.sh @@ -110,7 +110,7 @@ check_result 'L K J I H G F E D C B A' --full-history check_result 'K I H E C B A' --full-history -- file check_result 'K I H E C B A' --full-history --topo-order -- file check_result 'K I H E C B A' --full-history --date-order -- file -check_outcome failure 'I E C B A' --simplify-merges -- file +check_result 'I E C B A' --simplify-merges -- file check_result 'I B A' -- file check_result 'I B A' --topo-order -- file check_result 'H' --first-parent -- another-file |