revision: drop --show-all option

This was an undocumented debugging aid that does not seem to
have come in handy in the past decade, judging from its lack
of mentions on the mailing list.

Let's drop it in the name of simplicity. This is morally a
revert of 3131b71301 (Add "--show-all" revision walker flag
for debugging, 2008-02-09), but note that I did leave in the
mapping of UNINTERESTING to "^" in get_revision_mark(). I
don't think this would be possible to trigger with the
current code, but it's the only sensible marker.

We'll skip the usual deprecation period because this was
explicitly a debugging aid that was never documented.

Signed-off-by: Jeff King <peff@peff.net>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/revision.c b/revision.c
index 1f7454c..f4b1f72 100644
--- a/revision.c
+++ b/revision.c
@@ -1055,14 +1055,9 @@
 			return -1;
 		if (obj->flags & UNINTERESTING) {
 			mark_parents_uninteresting(commit);
-			if (revs->show_all)
-				p = &commit_list_insert(commit, p)->next;
 			slop = still_interesting(list, date, slop, &interesting_cache);
 			if (slop)
 				continue;
-			/* If showing all, add the whole pending list to the end */
-			if (revs->show_all)
-				*p = list;
 			break;
 		}
 		if (revs->min_age != -1 && (commit->date > revs->min_age))
@@ -1853,8 +1848,6 @@
 		revs->dense = 1;
 	} else if (!strcmp(arg, "--sparse")) {
 		revs->dense = 0;
-	} else if (!strcmp(arg, "--show-all")) {
-		revs->show_all = 1;
 	} else if (!strcmp(arg, "--in-commit-order")) {
 		revs->tree_blobs_in_commit_order = 1;
 	} else if (!strcmp(arg, "--remove-empty")) {
@@ -3061,8 +3054,6 @@
 		return commit_ignore;
 	if (revs->unpacked && has_sha1_pack(commit->object.oid.hash))
 		return commit_ignore;
-	if (revs->show_all)
-		return commit_show;
 	if (commit->object.flags & UNINTERESTING)
 		return commit_ignore;
 	if (revs->min_age != -1 &&
@@ -3161,7 +3152,6 @@
 	enum commit_action action = get_commit_action(revs, commit);
 
 	if (action == commit_show &&
-	    !revs->show_all &&
 	    revs->prune && revs->dense && want_ancestry(revs)) {
 		/*
 		 * --full-diff on simplified parents is no good: it
diff --git a/revision.h b/revision.h
index d7a35c8..187406b 100644
--- a/revision.h
+++ b/revision.h
@@ -90,7 +90,6 @@
 	unsigned int	dense:1,
 			prune:1,
 			no_walk:2,
-			show_all:1,
 			remove_empty_trees:1,
 			simplify_history:1,
 			topo_order:1,
diff --git a/t/t6015-rev-list-show-all-parents.sh b/t/t6015-rev-list-show-all-parents.sh
deleted file mode 100755
index 3c73c93..0000000
--- a/t/t6015-rev-list-show-all-parents.sh
+++ /dev/null
@@ -1,31 +0,0 @@
-#!/bin/sh
-
-test_description='--show-all --parents does not rewrite TREESAME commits'
-
-. ./test-lib.sh
-
-test_expect_success 'set up --show-all --parents test' '
-	test_commit one foo.txt &&
-	commit1=$(git rev-list -1 HEAD) &&
-	test_commit two bar.txt &&
-	commit2=$(git rev-list -1 HEAD) &&
-	test_commit three foo.txt &&
-	commit3=$(git rev-list -1 HEAD)
-	'
-
-test_expect_success '--parents rewrites TREESAME parents correctly' '
-	echo $commit3 $commit1 > expected &&
-	echo $commit1 >> expected &&
-	git rev-list --parents HEAD -- foo.txt > actual &&
-	test_cmp expected actual
-	'
-
-test_expect_success '--parents --show-all does not rewrites TREESAME parents' '
-	echo $commit3 $commit2 > expected &&
-	echo $commit2 $commit1 >> expected &&
-	echo $commit1 >> expected &&
-	git rev-list --parents --show-all HEAD -- foo.txt > actual &&
-	test_cmp expected actual
-	'
-
-test_done