rev-list --min-parents,--max-parents: doc, test and completion

This also adds test for "--merges" and "--no-merges" which we did not
have so far.

Signed-off-by: Michael J Gruber <git@drmicha.warpmail.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-rev-list.txt

@@ -16,6 +16,10 @@ SYNOPSIS
 	     [ \--sparse ]
 	     [ \--merges ]
 	     [ \--no-merges ]
+	     [ \--min-parents=<number> ]
+	     [ \--no-min-parents ]
+	     [ \--max-parents=<number> ]
+	     [ \--no-max-parents ]
 	     [ \--first-parent ]
 	     [ \--remove-empty ]
 	     [ \--full-history ]

Documentation/rev-list-options.txt

@@ -226,11 +226,26 @@ endif::git-rev-list[]
 
 --merges::
 
-	Print only merge commits.
+	Print only merge commits. This is exactly the same as `--min-parents=2`.
 
 --no-merges::
 
-	Do not print commits with more than one parent.
+	Do not print commits with more than one parent. This is
+	exactly the same as `--max-parents=1`.
+
+--min-parents=<number>::
+--max-parents=<number>::
+--no-min-parents::
+--no-max-parents::
+
+	Show only commits which have at least (or at most) that many
+	commits. In particular, `--max-parents=1` is the same as `--no-merges`,
+	`--min-parents=2` is the same as `--merges`.  `--max-parents=0`
+	gives all root commits and `--min-parents=3` all octopus merges.
++
+`--no-min-parents` and `--no-max-parents` reset these limits (to no limit)
+again.  Equivalent forms are `--min-parents=0` (any commit has 0 or more
+parents) and `--max-parents=-1` (negative numbers denote no upper limit).
 
 --first-parent::
 	Follow only the first parent commit upon seeing a merge

contrib/completion/git-completion.bash

@@ -1572,6 +1572,8 @@ __git_log_common_options="
 	--max-count=
 	--max-age= --since= --after=
 	--min-age= --until= --before=
+	--min-parents= --max-parents=
+	--no-min-parents --no-max-parents
 "
 # Options that go well for log and gitk (not shortlog)
 __git_log_gitk_options="

t/t6009-rev-list-parent.sh

@@ -1,9 +1,17 @@
 #!/bin/sh
 
-test_description='properly cull all ancestors'
+test_description='ancestor culling and limiting by parent number'
 
 . ./test-lib.sh
 
+check_revlist () {
+	rev_list_args="$1" &&
+	shift &&
+	git rev-parse "$@" >expect &&
+	git rev-list $rev_list_args --all >actual &&
+	test_cmp expect actual
+}
+
 test_expect_success setup '
 
 	touch file &&
@@ -28,4 +36,101 @@ test_expect_success 'one is ancestor of others and should not be shown' '
 
 '
 
+test_expect_success 'setup roots, merges and octopuses' '
+
+	git checkout --orphan newroot &&
+	test_commit five &&
+	git checkout -b sidebranch two &&
+	test_commit six &&
+	git checkout -b anotherbranch three &&
+	test_commit seven &&
+	git checkout -b yetanotherbranch four &&
+	test_commit eight &&
+	git checkout master &&
+	test_merge normalmerge newroot &&
+	test_tick &&
+	git merge -m tripus sidebranch anotherbranch &&
+	git tag tripus &&
+	git checkout -b tetrabranch normalmerge &&
+	test_tick &&
+	git merge -m tetrapus sidebranch anotherbranch yetanotherbranch &&
+	git tag tetrapus &&
+	git checkout master
+'
+
+test_expect_success 'rev-list roots' '
+
+	check_revlist "--max-parents=0" one five
+'
+
+test_expect_success 'rev-list no merges' '
+
+	check_revlist "--max-parents=1" one eight seven six five four three two &&
+	check_revlist "--no-merges" one eight seven six five four three two
+'
+
+test_expect_success 'rev-list no octopuses' '
+
+	check_revlist "--max-parents=2" one normalmerge eight seven six five four three two
+'
+
+test_expect_success 'rev-list no roots' '
+
+	check_revlist "--min-parents=1" tetrapus tripus normalmerge eight seven six four three two
+'
+
+test_expect_success 'rev-list merges' '
+
+	check_revlist "--min-parents=2" tetrapus tripus normalmerge &&
+	check_revlist "--merges" tetrapus tripus normalmerge
+'
+
+test_expect_success 'rev-list octopus' '
+
+	check_revlist "--min-parents=3" tetrapus tripus
+'
+
+test_expect_success 'rev-list ordinary commits' '
+
+	check_revlist "--min-parents=1 --max-parents=1" eight seven six four three two
+'
+
+test_expect_success 'rev-list --merges --no-merges yields empty set' '
+
+	check_revlist "--min-parents=2 --no-merges" &&
+	check_revlist "--merges --no-merges" &&
+	check_revlist "--no-merges --merges"
+'
+
+test_expect_success 'rev-list override and infinities' '
+
+	check_revlist "--min-parents=2 --max-parents=1 --max-parents=3" tripus normalmerge &&
+	check_revlist "--min-parents=1 --min-parents=2 --max-parents=7" tetrapus tripus normalmerge &&
+	check_revlist "--min-parents=2 --max-parents=8" tetrapus tripus normalmerge &&
+	check_revlist "--min-parents=2 --max-parents=-1" tetrapus tripus normalmerge &&
+	check_revlist "--min-parents=2 --no-max-parents" tetrapus tripus normalmerge &&
+	check_revlist "--max-parents=0 --min-parents=1 --no-min-parents" one five
+'
+
+test_expect_success 'set up dodecapus' '
+
+	for i in 1 2 3 4 5 6 7 8 9 10 11
+	do
+		git checkout -b root$i five || return
+		test_commit $i || return
+	done &&
+	git checkout master &&
+	test_tick &&
+	git merge -m dodecapus root{1,2,3,4,5,6,7,8,9,10,11} &&
+	git tag dodecapus
+'
+
+test_expect_success 'test with dodecapus' '
+
+	check_revlist "--min-parents=4" dodecapus tetrapus &&
+	check_revlist "--min-parents=8" dodecapus &&
+	check_revlist "--min-parents=12" dodecapus &&
+	check_revlist "--min-parents=13" &&
+	check_revlist "--min-parents=4 --max-parents=11" tetrapus
+'
 test_done