From f50c1da4e2ad755e8aaea1ee2124ad225d01c3b0 Mon Sep 17 00:00:00 2001
From: Pawel Kozlowski <pkozlowski.opensource@gmail.com>
Date: Fri, 7 Oct 2016 00:12:09 +0200
Subject: [PATCH] fix(forms): properly validate blank strings with minlength
 (#12091)

---
 modules/@angular/forms/src/validators.ts      | 14 ++++++-------
 .../@angular/forms/test/validators_spec.ts    | 20 +++++++++++++++----
 2 files changed, 22 insertions(+), 12 deletions(-)

diff --git a/modules/@angular/forms/src/validators.ts b/modules/@angular/forms/src/validators.ts
index 865cdc0d0d..f0bff67ecf 100644
--- a/modules/@angular/forms/src/validators.ts
+++ b/modules/@angular/forms/src/validators.ts
@@ -70,10 +70,9 @@ export class Validators {
    */
   static minLength(minLength: number): ValidatorFn {
     return (control: AbstractControl): {[key: string]: any} => {
-      if (isPresent(Validators.required(control))) return null;
-      var v: string = control.value;
-      return v.length < minLength ?
-          {'minlength': {'requiredLength': minLength, 'actualLength': v.length}} :
+      const length = typeof control.value === 'string' ? control.value.length : 0;
+      return length < minLength ?
+          {'minlength': {'requiredLength': minLength, 'actualLength': length}} :
           null;
     };
   }
@@ -83,10 +82,9 @@ export class Validators {
    */
   static maxLength(maxLength: number): ValidatorFn {
     return (control: AbstractControl): {[key: string]: any} => {
-      if (isPresent(Validators.required(control))) return null;
-      var v: string = control.value;
-      return v.length > maxLength ?
-          {'maxlength': {'requiredLength': maxLength, 'actualLength': v.length}} :
+      const length = typeof control.value === 'string' ? control.value.length : 0;
+      return length > maxLength ?
+          {'maxlength': {'requiredLength': maxLength, 'actualLength': length}} :
           null;
     };
   }
diff --git a/modules/@angular/forms/test/validators_spec.ts b/modules/@angular/forms/test/validators_spec.ts
index 280a3241fd..83b0c2effb 100644
--- a/modules/@angular/forms/test/validators_spec.ts
+++ b/modules/@angular/forms/test/validators_spec.ts
@@ -51,11 +51,23 @@ export function main() {
     });
 
     describe('minLength', () => {
-      it('should not error on an empty string',
-         () => { expect(Validators.minLength(2)(new FormControl(''))).toEqual(null); });
+      it('should error on an empty string', () => {
+        expect(Validators.minLength(2)(new FormControl(''))).toEqual({
+          'minlength': {'requiredLength': 2, 'actualLength': 0}
+        });
+      });
 
-      it('should not error on null',
-         () => { expect(Validators.minLength(2)(new FormControl(null))).toEqual(null); });
+      it('should error on null', () => {
+        expect(Validators.minLength(2)(new FormControl(null))).toEqual({
+          'minlength': {'requiredLength': 2, 'actualLength': 0}
+        });
+      });
+
+      it('should error on undefined', () => {
+        expect(Validators.minLength(2)(new FormControl(null))).toEqual({
+          'minlength': {'requiredLength': 2, 'actualLength': 0}
+        });
+      });
 
       it('should not error on valid strings',
          () => { expect(Validators.minLength(2)(new FormControl('aa'))).toEqual(null); });