add--interactive: compute the empty tree value

bk2204 · gitster · commit 23ec4c51d53f · 2018-05-02T13:59:53.000+09:00
The interactive add script hard-codes the object ID of the empty tree.
To avoid any problems when changing hashes, compute this value when used
and cache it for any future uses.

Signed-off-by: brian m. carlson &lt;sandals@crustytoothpaste.net&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/git-add--interactive.perl b/git-add--interactive.perl
@@ -205,8 +205,15 @@ sub list_untracked {
 	}
 }
 
-sub get_empty_tree {
-	return '4b825dc642cb6eb9a060e54bf8d69288fbee4904';
+{
+	my $empty_tree;
+	sub get_empty_tree {
+		return $empty_tree if defined $empty_tree;
+
+		$empty_tree = run_cmd_pipe(qw(git hash-object -t tree /dev/null));
+		chomp $empty_tree;
+		return $empty_tree;
+	}
 }
 
 sub get_diff_reference {

Original file line number	Diff line number	Diff line change
`@@ -205,8 +205,15 @@ sub list_untracked {`
`205`	`205`	`}`
`206`	`206`	`}`
`207`	`207`
`208`		`-sub get_empty_tree {`
`209`		`- return '4b825dc642cb6eb9a060e54bf8d69288fbee4904';`
	`208`	`+{`
	`209`	`+ my $empty_tree;`
	`210`	`+ sub get_empty_tree {`
	`211`	`+ return $empty_tree if defined $empty_tree;`
	`212`	`+`
	`213`	`+ $empty_tree = run_cmd_pipe(qw(git hash-object -t tree /dev/null));`
	`214`	`+ chomp $empty_tree;`
	`215`	`+ return $empty_tree;`
	`216`	`+ }`
`210`	`217`	`}`
`211`	`218`
`212`	`219`	`sub get_diff_reference {`