ref/refname: Add refname validation

1 files changed, 13 insertions, 0 deletions

diff --git a/ref/refname/root_syntax.go b/ref/refname/root_syntax.go
new file mode 100644
index 00000000..97a15cb9
--- /dev/null
+++ b/ref/refname/root_syntax.go
@@ -0,0 +1,13 @@
+package refname
+
+// IsRootSyntax reports whether name matches Git's all-caps root-ref syntax.
+func IsRootSyntax(name string) bool {
+	for i := range len(name) {
+		ch := name[i]
+		if (ch < 'A' || ch > 'Z') && ch != '-' && ch != '_' {
+			return false
+		}
+	}
+
+	return true
+}