git-status: respect core.excludesFile

git-add reads this variable, and honours the contents of that file if that
exists. Match this behaviour in git-status, too.

Noticed by Evan Carroll on IRC.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/config.txt

@@ -263,6 +263,11 @@ You probably do not need to adjust this value.
 +
 Common unit suffixes of 'k', 'm', or 'g' are supported.
 
+core.excludeFile::
+	In addition to '.gitignore' (per-directory) and
+	'.git/info/exclude', git looks into this file for patterns
+	of files which are not meant to be tracked.
+
 alias.*::
 	Command aliases for the gitlink:git[1] command wrapper - e.g.
 	after defining "alias.last = cat-file commit HEAD", the invocation

Documentation/git-status.txt

@@ -42,6 +42,11 @@ mean the same thing and the latter is kept for backward
 compatibility) and `color.status.<slot>` configuration variables
 to colorize its output.
 
+As for gitlink:git-add[1], the configuration variable
+'core.excludesfile' can indicate a path to a file containing patterns
+of file names to exclude, in addition to patterns given in
+'info/exclude' and '.gitignore'.
+
 
 Author
 ------

t/t3001-ls-files-others-exclude.sh

@@ -79,4 +79,24 @@ test_expect_success \
        >output &&
      git diff expect output'
 
+cat > excludes-file << EOF
+*.[1-8]
+e*
+EOF
+
+git-config core.excludesFile excludes-file
+
+git-runstatus | grep "^#	" > output
+
+cat > expect << EOF
+#	.gitignore
+#	a.6
+#	one/
+#	output
+#	three/
+EOF
+
+test_expect_success 'git-status honours core.excludesfile' \
+	'diff -u expect output'
+
 test_done

wt-status.c

@@ -22,6 +22,7 @@ static const char use_add_rm_msg[] =
 "use \"git add/rm <file>...\" to update what will be committed";
 static const char use_add_to_include_msg[] =
 "use \"git add <file>...\" to include in what will be committed";
+static const char *excludes_file;
 
 static int parse_status_slot(const char *var, int offset)
 {
@@ -259,6 +260,8 @@ static void wt_status_print_untracked(struct wt_status *s)
 	x = git_path("info/exclude");
 	if (file_exists(x))
 		add_excludes_from_file(&dir, x);
+	if (excludes_file && file_exists(excludes_file))
+		add_excludes_from_file(&dir, excludes_file);
 
 	read_directory(&dir, ".", "", 0);
 	for(i = 0; i < dir.nr; i++) {
@@ -356,5 +359,11 @@ int git_status_config(const char *k, const char *v)
 		int slot = parse_status_slot(k, 13);
 		color_parse(v, k, wt_status_colors[slot]);
 	}
+	if (!strcmp(k, "core.excludesfile")) {
+		if (!v)
+			die("core.excludesfile without value");
+		excludes_file = xstrdup(v);
+		return 0;
+	}
 	return git_default_config(k, v);
 }