[PATCH v3 0/2] revision.c: implement --reverse=before for walks

[Mirko Faina <mroik@delayed.space>]

I've fixed the docs with the suggested changes by Jeff and applied some
styling fixes.

[1/2] revision.c: implement --reverse=before for walks (Mirko Faina)
[2/2] revision.c: reduce memory usage on reverse before (Mirko Faina)

 Documentation/rev-list-options.adoc | 16 +++++--
 revision.c                          | 73 +++++++++++++++++++++++++++--
 revision.h                          |  8 +++-
 t/t4202-log.sh                      | 66 ++++++++++++++++++++++++++
 4 files changed, 153 insertions(+), 10 deletions(-)

Range-diff against v2:
1:  599a247d82 ! 1:  4864ac46dd revision.c: implement --reverse=before for walks
    @@ Documentation/rev-list-options.adoc: With `--topo-order`, they would show 8 6 5
     +	`--walk-reflogs`. If `after`, output the commits chosen to be
     +	shown (see 'Commit Limiting' section above) in reverse order. If
     +	`before`, reverse the commits before filtering with `Commit
    -+	Limiting` options. This option can be used multiple times, last
    -+	one is applied. When the argument for `--reverse` is omitted, if
    -+	the current state is in no reverse, it defaults to `after`. If
    -+	it is in any reversed state, it restores the original ordering
    -+	by removing the reverse state.
    ++	Limiting` options. When multiple `--reverse=` options are given,
    ++	the final option overrides any previous options. The `--reverse`
    ++	option (with no specifier) behaves as `--reverse=after`, except
    ++	that, for historical reasons, it negates any previous reversed
    ++	state (so `--reverse --reverse` does nothing, nor does
    ++	`--reverse=before --reverse`. Note that `--reverse=before
    ++	--reverse --reverse` is the same as `--reverse=after`).
      endif::git-shortlog[]
      
      ifndef::git-shortlog[]
2:  480b322cf8 ! 2:  00489b0e52 revision.c: reduce memory usage on reverse before
    @@ revision.c: static struct commit *get_revision_internal(struct rev_info *revs)
      }
      
     +static void retrieve_with_window(struct rev_info *revs, int max_count,
    -+			  struct commit_list **reversed)
    ++			  	 struct commit_list **reversed)
     +{
     +	struct commit *c;
     +	struct commit_list *into_queue = NULL;
    @@ revision.c: static struct commit *get_revision_internal(struct rev_info *revs)
     +		}
     +	}
     +
    -+	while (outo_count) {
    -+		c = pop_commit(&outo_queue);
    -+		outo_count--;
    ++	while ((c = pop_commit(&outo_queue)))
     +		commit_list_insert(c, reversed);
    -+	}
    -+
    -+	while (into_count) {
    -+		c = pop_commit(&into_queue);
    -+		into_count--;
    ++	while ((c = pop_commit(&into_queue)))
     +		commit_list_insert(c, &outo_queue);
    -+		outo_count++;
    -+	}
    -+
    -+	while (outo_count) {
    -+		c = pop_commit(&outo_queue);
    -+		outo_count--;
    ++	while ((c = pop_commit(&outo_queue)))
     +		commit_list_insert(c, reversed);
    -+	}
     +}
     +
      struct commit *get_revision(struct rev_info *revs)
-- 
2.54.0