Subject: [PATCH] show-branch: --no-sparse should give dense output

From: Junio C Hamano <[email-masked]>
Date: Wed, 19 Jul 2023 04:37:39 -0700

"git show-branch --no-sparse" behaved exactly the same way as "git
show-branch --sparse", which did not make any sense.  This was
because it used a variable "dense" initialized to 1 by default to
give "non sparse" behaviour, and OPT_SET_INT() to set the varilable
to 0 in response to the "--sparse" option.  Unfortunately,
OPT_SET_INT() sets 0 to the given variable when the option is
negated.

Flip the polarity of the variable "dense" by renaming it to "sparse"
and initializing it to 0, and have OPT_SET_INT() set the variable to
1 when "--sparse" is given.  This way, "--no-sparse" would set 0 to
the variable and would give us the "dense" behaviour.

Signed-off-by: Junio C Hamano <[email-masked]>
---
 builtin/show-branch.c  |  8 ++++----
 t/t3202-show-branch.sh | 16 ++++++++++++++++
 2 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/builtin/show-branch.c b/builtin/show-branch.c
index 7ef4a642c1..67f3ef0639 100644
--- a/builtin/show-branch.c
+++ b/builtin/show-branch.c
@@ -645,7 +645,7 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 	int with_current_branch = 0;
 	int head_at = -1;
 	int topics = 0;
-	int dense = 1;
+	int sparse = 0;
 	const char *reflog_base = NULL;
 	struct option builtin_show_branch_options[] = {
 		OPT_BOOL('a', "all", &all_heads,
@@ -672,8 +672,8 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 			    REV_SORT_IN_GRAPH_ORDER),
 		OPT_BOOL(0, "topics", &topics,
 			 N_("show only commits not on the first branch")),
-		OPT_SET_INT(0, "sparse", &dense,
-			    N_("show merges reachable from only one tip"), 0),
+		OPT_SET_INT(0, "sparse", &sparse,
+			    N_("show merges reachable from only one tip"), 1),
 		OPT_SET_INT(0, "date-order", &sort_order,
 			    N_("topologically sort, maintaining date order "
 			       "where possible"),
@@ -936,7 +936,7 @@ int cmd_show_branch(int ac, const char **av, const char *prefix)
 			    !is_merge_point &&
 			    (this_flag & (1u << REV_SHIFT)))
 				continue;
-			if (dense && is_merge &&
+			if (!sparse && is_merge &&
 			    omit_in_dense(commit, rev, num_rev))
 				continue;
 			for (i = 0; i < num_rev; i++) {
diff --git a/t/t3202-show-branch.sh b/t/t3202-show-branch.sh
index be20ebe1d5..ca7c44f0f7 100755
--- a/t/t3202-show-branch.sh
+++ b/t/t3202-show-branch.sh
@@ -119,6 +119,22 @@ test_expect_success 'show branch --remotes' '
 	test_must_be_empty actual.out
 '
 
+test_expect_success 'show-branch --sparse' '
+	test_when_finished "git checkout branch10 && git branch -D branchA" &&
+	git checkout -b branchA branch10 &&
+	git merge -s ours -m "merge 1 and 10 to make A" branch1 &&
+	git commit --allow-empty -m "another" &&
+
+	git show-branch --sparse >out &&
+	grep "merge 1 and 10 to make A" out &&
+
+	git show-branch >out &&
+	! grep "merge 1 and 10 to make A" out &&
+
+	git show-branch --no-sparse >out &&
+	! grep "merge 1 and 10 to make A" out
+'
+
 test_expect_success 'setup show branch --list' '
 	sed "s/^> //" >expect <<-\EOF
 	>   [branch1] branch1
-- 
2.41.0-376-gcba07a324d