From bc32ebfe1cf7b0baf9765d657ba1a5f277936e76 Mon Sep 17 00:00:00 2001
From: Dane Harrigan <72265290+dane@users.noreply.github.com>
Date: Wed, 1 Dec 2021 23:45:50 -0800
Subject: [PATCH] Each function passes the correct value or pointer to rules.

The combination of Elem().Interface() does not return a pointer, even if the
original variable was a pointer. Passing by value to validation rules becomes a
problem when the value is a struct with a private mutex. This is the case with
structs generated with protoc-gen-go. `go vet`'s copylocks check identifies the
problem.
---
 each.go      |  2 +-
 each_test.go | 13 +++++++++++++
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/each.go b/each.go
index 2cc7253..8eb022c 100644
--- a/each.go
+++ b/each.go
@@ -78,7 +78,7 @@ func (r EachRule) getInterface(value reflect.Value) interface{} {
 		if value.IsNil() {
 			return nil
 		}
-		return value.Elem().Interface()
+		return value.Interface()
 	default:
 		return value.Interface()
 	}
diff --git a/each_test.go b/each_test.go
index 4199afd..731059e 100644
--- a/each_test.go
+++ b/each_test.go
@@ -72,3 +72,16 @@ func TestEachWithContext(t *testing.T) {
 		assertError(t, test.err, err, test.tag)
 	}
 }
+
+func TestEachAndBy(t *testing.T) {
+	var byAddr bool
+	var s string
+	Each(By(func(v interface{}) error {
+		_, byAddr = v.(*string)
+		return nil
+	})).Validate([]*string{&s})
+
+	if !byAddr {
+		t.Fatal("slice of pointers does not get passed to `By` function by ref")
+	}
+}