attr: add attr.tree for setting the treeish to read attributes from

44451a2 (attr: teach "--attr-source=<tree>" global option to "git",
2023-05-06) provided the ability to pass in a treeish as the attr
source. In the context of serving Git repositories as bare repos like we
do at GitLab however, it would be easier to point --attr-source to HEAD
for all commands by setting it once.

Add a new config attr.tree that allows this.

Signed-off-by: John Cai <johncai86@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/config.c b/config.c
index 3846a37be9..fb6a2db1d9 100644
--- a/config.c
+++ b/config.c
@@ -18,6 +18,7 @@
 #include "repository.h"
 #include "lockfile.h"
 #include "mailmap.h"
+#include "attr.h"
 #include "exec-cmd.h"
 #include "strbuf.h"
 #include "quote.h"
@@ -1904,6 +1905,18 @@ static int git_default_mailmap_config(const char *var, const char *value)
 	return 0;
 }
 
+static int git_default_attr_config(const char *var, const char *value)
+{
+	if (!strcmp(var, "attr.tree"))
+		return git_config_string(&git_attr_tree, var, value);
+
+	/*
+	 * Add other attribute related config variables here and to
+	 * Documentation/config/attr.txt.
+	 */
+	return 0;
+}
+
 int git_default_config(const char *var, const char *value,
 		       const struct config_context *ctx, void *cb)
 {
@@ -1927,6 +1940,9 @@ int git_default_config(const char *var, const char *value,
 	if (starts_with(var, "mailmap."))
 		return git_default_mailmap_config(var, value);
 
+	if (starts_with(var, "attr."))
+		return git_default_attr_config(var, value);
+
 	if (starts_with(var, "advice.") || starts_with(var, "color.advice"))
 		return git_default_advice_config(var, value);