[PATCH 2/2] notes: fix minimum number of parameters to "copy" subcommand

[Doan Tran Cong Danh <congdanhqx@gmail.com>]

The builtin/notes.c::copy() function is prepared to handle either
one or two arguments given from the command line;
in case of one argument is given, to-obj defaults to HEAD.

When bbb1b8a3 ("notes: check number of parameters to "git notes copy"",
2010-06-28) tried to make sure "git notes copy" (with *no* other
argument) does not dereference NULL by making sure we did not get
too few parameters, it incorrectly insisted that we need two arguments,
instead of either one or two.
This disabled the defaulting to-obj to HEAD.
Correct it.

Signed-off-by: Doan Tran Cong Danh <congdanhqx@gmail.com>
---
 Documentation/git-notes.txt |  6 +++---
 builtin/notes.c             |  2 +-
 t/t3301-notes.sh            | 40 +++++++++++++++++++++++++++++++++++--
 3 files changed, 42 insertions(+), 6 deletions(-)

diff --git a/Documentation/git-notes.txt b/Documentation/git-notes.txt
index f56a5a9197..ced2e8280e 100644
--- a/Documentation/git-notes.txt
+++ b/Documentation/git-notes.txt
@@ -10,7 +10,7 @@ SYNOPSIS
 [verse]
 'git notes' [list [<object>]]
 'git notes' add [-f] [--allow-empty] [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
-'git notes' copy [-f] ( --stdin | <from-object> <to-object> )
+'git notes' copy [-f] ( --stdin | <from-object> [<to-object>] )
 'git notes' append [--allow-empty] [-F <file> | -m <msg> | (-c | -C) <object>] [<object>]
 'git notes' edit [--allow-empty] [<object>]
 'git notes' show [<object>]
@@ -68,8 +68,8 @@ add::
 	subcommand).
 
 copy::
-	Copy the notes for the first object onto the second object.
-	Abort if the second object already has notes, or if the first
+	Copy the notes for the first object onto the second object (defaults to
+	HEAD). Abort if the second object already has notes, or if the first
 	object has none (use -f to overwrite existing notes to the
 	second object). This subcommand is equivalent to:
 	`git notes add [-f] -C $(git notes list <from-object>) <to-object>`
diff --git a/builtin/notes.c b/builtin/notes.c
index 02e97f55c5..95456f3165 100644
--- a/builtin/notes.c
+++ b/builtin/notes.c
@@ -513,7 +513,7 @@ static int copy(int argc, const char **argv, const char *prefix)
 		}
 	}
 
-	if (argc < 2) {
+	if (argc < 1) {
 		error(_("too few parameters"));
 		usage_with_options(git_notes_copy_usage, options);
 	}
diff --git a/t/t3301-notes.sh b/t/t3301-notes.sh
index d7767e4438..d66a5f6faa 100755
--- a/t/t3301-notes.sh
+++ b/t/t3301-notes.sh
@@ -864,6 +864,24 @@ test_expect_success 'append to note from other note with "git notes append -c"'
 '
 
 test_expect_success 'copy note with "git notes copy"' '
+	commit=$(git rev-parse 4th) &&
+	cat >expect <<-EOF &&
+		commit $commit
+		Author: A U Thor <author@example.com>
+		Date:   Thu Apr 7 15:16:13 2005 -0700
+
+		${indent}4th
+
+		Notes:
+		${indent}This is a blob object
+	EOF
+	git notes copy 8th 4th &&
+	git log 3rd..4th >actual &&
+	test_cmp expect actual &&
+	test "$(git note list 4th)" = "$(git note list 8th)"
+'
+
+test_expect_success 'copy note with "git notes copy" with default' '
 	test_commit 11th &&
 	commit=$(git rev-parse HEAD) &&
 	cat >expect <<-EOF &&
@@ -878,7 +896,7 @@ test_expect_success 'copy note with "git notes copy"' '
 		${indent}
 		${indent}yet another note
 	EOF
-	git notes copy HEAD^ HEAD &&
+	git notes copy HEAD^ &&
 	git log -1 >actual &&
 	test_cmp expect actual &&
 	test "$(git notes list HEAD)" = "$(git notes list HEAD^)"
@@ -892,6 +910,24 @@ test_expect_success 'prevent overwrite with "git notes copy"' '
 '
 
 test_expect_success 'allow overwrite with "git notes copy -f"' '
+	commit=$(git rev-parse HEAD) &&
+	cat >expect <<-EOF &&
+		commit $commit
+		Author: A U Thor <author@example.com>
+		Date:   Thu Apr 7 15:23:13 2005 -0700
+
+		${indent}11th
+
+		Notes:
+		${indent}This is a blob object
+	EOF
+	git notes copy -f HEAD~3 HEAD &&
+	git log -1 >actual &&
+	test_cmp expect actual &&
+	test "$(git notes list HEAD)" = "$(git notes list HEAD~3)"
+'
+
+test_expect_success 'allow overwrite with "git notes copy -f" with default' '
 	commit=$(git rev-parse HEAD) &&
 	cat >expect <<-EOF &&
 		commit $commit
@@ -905,7 +941,7 @@ test_expect_success 'allow overwrite with "git notes copy -f"' '
 		${indent}
 		${indent}yet another note
 	EOF
-	git notes copy -f HEAD~2 HEAD &&
+	git notes copy -f HEAD~2 &&
 	git log -1 >actual &&
 	test_cmp expect actual &&
 	test "$(git notes list HEAD)" = "$(git notes list HEAD~2)"
-- 
2.23.0