symfony
diff --git a/‎src/Symfony/Component/Mailer/EventListener/MessageListener.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mailer/EventListener/MessageListener.php
+1-1Lines changed: 1 addition & 1 deletion b/‎src/Symfony/Component/Mailer/EventListener/MessageListener.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mailer/EventListener/MessageListener.php
+1-1Lines changed: 1 addition & 1 deletion
diff --git a/‎src/Symfony/Component/Mailer/Tests/EventListener/MessageListenerTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mailer/Tests/EventListener/MessageListenerTest.php
+12Lines changed: 12 additions & 0 deletions b/‎src/Symfony/Component/Mailer/Tests/EventListener/MessageListenerTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mailer/Tests/EventListener/MessageListenerTest.php
+12Lines changed: 12 additions & 0 deletions
diff --git a/‎src/Symfony/Component/Mime/Header/Headers.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mime/Header/Headers.php
+2-2Lines changed: 2 additions & 2 deletions b/‎src/Symfony/Component/Mime/Header/Headers.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mime/Header/Headers.php
+2-2Lines changed: 2 additions & 2 deletions
diff --git a/‎src/Symfony/Component/Mime/Tests/Header/HeadersTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mime/Tests/Header/HeadersTest.php
+14Lines changed: 14 additions & 0 deletions b/‎src/Symfony/Component/Mime/Tests/Header/HeadersTest.php
Copy file name to clipboardExpand all lines: src/Symfony/Component/Mime/Tests/Header/HeadersTest.php
+14Lines changed: 14 additions & 0 deletions
@@ -58,7 +58,7 @@ public function addHeaderRule(string $headerName, int $rule): void
             throw new InvalidArgumentException(sprintf('The "%d" rule is not supported.', $rule));
         }
 
-        $this->headerRules[$headerName] = $rule;
+        $this->headerRules[strtolower($headerName)] = $rule;
     }
 
     public function onMessage(MessageEvent $event): void
 
@@ -101,5 +101,17 @@ public function provideHeaders(): iterable
             ->add(new MailboxListHeader('bcc', [new Address('bcc-initial@example.com'), new Address('bcc-default@example.com'), new Address('bcc-default-1@example.com')]))
         ;
         yield 'bcc, add another bcc (unique header)' => [$initialHeaders, $defaultHeaders, $expectedHeaders];
+
+        $initialHeaders = (new Headers())
+            ->add(new UnstructuredHeader('foo', 'initial'))
+        ;
+        $defaultHeaders = (new Headers())
+            ->add(new UnstructuredHeader('foo', 'bar'))
+            ->add(new UnstructuredHeader('bar', 'foo'))
+        ;
+        $rules = [
+            'Foo' => MessageListener::HEADER_REPLACE,
+        ];
+        yield 'Capitalized header rule (case-insensitive), replace if set' => [$initialHeaders, $defaultHeaders, $defaultHeaders, $rules];
     }
 }
@@ -143,7 +143,7 @@ public function addParameterizedHeader(string $name, string $value, array $param
      */
     public function addHeader(string $name, $argument, array $more = []): self
     {
-        $parts = explode('\\', self::HEADER_CLASS_MAP[$name] ?? UnstructuredHeader::class);
+        $parts = explode('\\', self::HEADER_CLASS_MAP[strtolower($name)] ?? UnstructuredHeader::class);
         $method = 'add'.ucfirst(array_pop($parts));
         if ('addUnstructuredHeader' === $method) {
             $method = 'addTextHeader';
@@ -217,7 +217,7 @@ public function remove(string $name): void
 
     public static function isUniqueHeader(string $name): bool
     {
-        return \in_array($name, self::UNIQUE_HEADERS, true);
+        return \in_array(strtolower($name), self::UNIQUE_HEADERS, true);
     }
 
     /**
 
@@ -239,6 +239,20 @@ public function testRemoveIsNotCaseSensitive()
         $this->assertFalse($headers->has('Message-ID'));
     }
 
+    public function testAddHeaderIsNotCaseSensitive()
+    {
+        $headers = new Headers();
+        $headers->addHeader('From', ['from@example.com']);
+
+        $this->assertInstanceOf(MailboxListHeader::class, $headers->get('from'));
+        $this->assertEquals([new Address('from@example.com')], $headers->get('from')->getBody());
+    }
+
+    public function testIsUniqueHeaderIsNotCaseSensitive()
+    {
+        $this->assertTrue(Headers::isUniqueHeader('From'));
+    }
+
     public function testToStringJoinsHeadersTogether()
     {
         $headers = new Headers();
Original file line number	Diff line number	Diff line change
`@@ -58,7 +58,7 @@ public function addHeaderRule(string $headerName, int $rule): void`
`58`	`58`	`throw new InvalidArgumentException(sprintf('The "%d" rule is not supported.', $rule));`
`59`	`59`	`}`
`60`	`60`
`61`		`- $this->headerRules[$headerName] = $rule;`
	`61`	`+ $this->headerRules[strtolower($headerName)] = $rule;`
`62`	`62`	`}`
`63`	`63`
`64`	`64`	`public function onMessage(MessageEvent $event): void`
Original file line number	Diff line number	Diff line change
`@@ -101,5 +101,17 @@ public function provideHeaders(): iterable`
`101`	`101`	`->add(new MailboxListHeader('bcc', [new Address('bcc-initial@example.com'), new Address('bcc-default@example.com'), new Address('bcc-default-1@example.com')]))`
`102`	`102`	`;`
`103`	`103`	`yield 'bcc, add another bcc (unique header)' => [$initialHeaders, $defaultHeaders, $expectedHeaders];`
	`104`	`+`
	`105`	`+ $initialHeaders = (new Headers())`
	`106`	`+ ->add(new UnstructuredHeader('foo', 'initial'))`
	`107`	`+ ;`
	`108`	`+ $defaultHeaders = (new Headers())`
	`109`	`+ ->add(new UnstructuredHeader('foo', 'bar'))`
	`110`	`+ ->add(new UnstructuredHeader('bar', 'foo'))`
	`111`	`+ ;`
	`112`	`+ $rules = [`
	`113`	`+ 'Foo' => MessageListener::HEADER_REPLACE,`
	`114`	`+ ];`
	`115`	`+ yield 'Capitalized header rule (case-insensitive), replace if set' => [$initialHeaders, $defaultHeaders, $defaultHeaders, $rules];`
`104`	`116`	`}`
`105`	`117`	`}`
Original file line number	Diff line number	Diff line change
`@@ -143,7 +143,7 @@ public function addParameterizedHeader(string $name, string $value, array $param`
`143`	`143`	`*/`
`144`	`144`	`public function addHeader(string $name, $argument, array $more = []): self`
`145`	`145`	`{`
`146`		`- $parts = explode('\\', self::HEADER_CLASS_MAP[$name] ?? UnstructuredHeader::class);`
	`146`	`+ $parts = explode('\\', self::HEADER_CLASS_MAP[strtolower($name)] ?? UnstructuredHeader::class);`
`147`	`147`	`$method = 'add'.ucfirst(array_pop($parts));`
`148`	`148`	`if ('addUnstructuredHeader' === $method) {`
`149`	`149`	`$method = 'addTextHeader';`
`@@ -217,7 +217,7 @@ public function remove(string $name): void`
`217`	`217`
`218`	`218`	`public static function isUniqueHeader(string $name): bool`
`219`	`219`	`{`
`220`		`- return \in_array($name, self::UNIQUE_HEADERS, true);`
	`220`	`+ return \in_array(strtolower($name), self::UNIQUE_HEADERS, true);`
`221`	`221`	`}`
`222`	`222`
`223`	`223`	`/**`