Request->getHeader() should always return a string

PHPDoc (of the public API) says that this method returns string but it also returns null, which is not allowed in some method calls. This fixes that behaviour and returns an empty string and fixes all code paths that explicitly checked for null to be still compliant.

Found while enabling the strict_typing for lib/private for the PHP7+ migration.

Signed-off-by: Morris Jobke <hey@morrisjobke.de>

4 files changed, 9 insertions, 7 deletions

diff --git a/lib/private/AppFramework/Http/Request.php b/lib/private/AppFramework/Http/Request.php
index 77ecb02165b..975c4255d5a 100644
--- a/lib/private/AppFramework/Http/Request.php
+++ b/lib/private/AppFramework/Http/Request.php
@@ -324,7 +324,7 @@ class Request implements \ArrayAccess, \Countable, IRequest {
 
 		}
 
-		return null;
+		return '';
 	}
 
 	/**
@@ -404,8 +404,7 @@ class Request implements \ArrayAccess, \Countable, IRequest {
 	protected function getContent() {
 		// If the content can't be parsed into an array then return a stream resource.
 		if ($this->method === 'PUT'
-			&& $this->getHeader('Content-Length') !== 0
-			&& $this->getHeader('Content-Length') !== null
+			&& $this->getHeader('Content-Length') !== '0'
 			&& $this->getHeader('Content-Length') !== ''
 			&& strpos($this->getHeader('Content-Type'), 'application/x-www-form-urlencoded') === false
 			&& strpos($this->getHeader('Content-Type'), 'application/json') === false
diff --git a/lib/private/L10N/Factory.php b/lib/private/L10N/Factory.php
index e277a00e653..8268be05d4b 100644
--- a/lib/private/L10N/Factory.php
+++ b/lib/private/L10N/Factory.php
@@ -247,7 +247,7 @@ class Factory implements IFactory {
 	 */
 	private function getLanguageFromRequest($app) {
 		$header = $this->request->getHeader('ACCEPT_LANGUAGE');
-		if ($header) {
+		if ($header !== '') {
 			$available = $this->findAvailableLanguages($app);
 
 			// E.g. make sure that 'de' is before 'de_DE'.
diff --git a/lib/private/Log/File.php b/lib/private/Log/File.php
index b6a208ad68a..290f7897c9d 100644
--- a/lib/private/Log/File.php
+++ b/lib/private/Log/File.php
@@ -105,7 +105,10 @@ class File {
 		} else {
 			$user = '--';
 		}
-		$userAgent = $request->getHeader('User-Agent') ?: '--';
+		$userAgent = $request->getHeader('User-Agent');
+		if ($userAgent === '') {
+			$userAgent = '--';
+		}
 		$version = $config->getValue('version', '');
 		$entry = compact(
 			'reqId',
diff --git a/lib/private/Memcache/APCu.php b/lib/private/Memcache/APCu.php
index 70f0d73d2d4..3e96acdecb7 100644
--- a/lib/private/Memcache/APCu.php
+++ b/lib/private/Memcache/APCu.php
@@ -158,8 +158,8 @@ class APCu extends Cache implements IMemcache {
 		} elseif (!\OC::$server->getIniWrapper()->getBool('apc.enable_cli') && \OC::$CLI) {
 			return false;
 		} elseif (
-				version_compare(phpversion('apc'), '4.0.6') === -1 &&
-				version_compare(phpversion('apcu'), '5.1.0') === -1
+				version_compare(phpversion('apc') ?: '0.0.0', '4.0.6') === -1 &&
+				version_compare(phpversion('apcu') ?: '0.0.0', '5.1.0') === -1
 		) {
 			return false;
 		} else {