git-configurable-gitignore-filename.diff

diff --git a/cache.h b/cache.h
index fcb511d..7f37595 100644
--- a/cache.h
+++ b/cache.h
@@ -1389,6 +1389,7 @@ extern int check_pager_config(const char *cmd);
 
 extern const char *editor_program;
 extern const char *askpass_program;
+extern const char *excludes_default_filename;
 extern const char *excludes_file;
 
 /* base85 */
diff --git a/config.c b/config.c
index 058505c..ed33e1d 100644
--- a/config.c
+++ b/config.c
@@ -832,6 +832,9 @@ static int git_default_core_config(const char *var, const char *value)
 	if (!strcmp(var, "core.askpass"))
 		return git_config_string(&askpass_program, var, value);
 
+	if (!strcmp(var, "core.excludesdefaultfilename"))
+		return git_config_string(&excludes_default_filename, var, value);
+
 	if (!strcmp(var, "core.excludesfile"))
 		return git_config_pathname(&excludes_file, var, value);
 
diff --git a/dir.c b/dir.c
index fcb6872..ea45d1a 100644
--- a/dir.c
+++ b/dir.c
@@ -1620,7 +1620,12 @@ void setup_standard_excludes(struct dir_struct *dir)
 	const char *path;
 	char *xdg_path;
 
-	dir->exclude_per_dir = ".gitignore";
+	if (excludes_default_filename) {
+		dir->exclude_per_dir = excludes_default_filename;
+	} else {
+		dir->exclude_per_dir = ".gitignore";
+	}
+
 	path = git_path("info/exclude");
 	if (!excludes_file) {
 		home_config_paths(NULL, &xdg_path, "ignore");
diff --git a/environment.c b/environment.c
index 565f652..d174d20 100644
--- a/environment.c
+++ b/environment.c
@@ -43,6 +43,7 @@ const char *pager_program;
 int pager_use_color = 1;
 const char *editor_program;
 const char *askpass_program;
+const char *excludes_default_filename;
 const char *excludes_file;
 enum auto_crlf auto_crlf = AUTO_CRLF_FALSE;
 int check_replace_refs = 1;