Fix array access to nullable property

Trying to access array offset on value of type null (protected/models/User.php:318)

Stack trace:
#0 yii/framework/base/CComponent.php(111): User->getUpicUrl()
#1 yii/framework/db/ar/CActiveRecord.php(145): User->__get()
basavind#2 protected/views/users/profile_head.php(15): User->__get()
basavind#3 yii/framework/web/CBaseController.php(126): require()
basavind#4 yii/framework/web/CBaseController.php(95): UsersController->renderInternal()
basavind#5 yii/framework/web/CController.php(872): UsersController->renderFile()
basavind#6 protected/views/users/books.php(15): UsersController->renderPartial()
uisky#7 yii/framework/web/CBaseController.php(126): require()
uisky#8 yii/framework/web/CBaseController.php(95): UsersController->renderInternal()
uisky#9 yii/framework/web/CController.php(872): UsersController->renderFile()
uisky#10 yii/framework/web/CController.php(785): UsersController->renderPartial()
uisky#11 protected/controllers/UsersController.php(186): UsersController->render()
uisky#12 unknown(0): UsersController->actionBooks()
uisky#13 yii/framework/web/actions/CAction.php(115): ReflectionMethod->invokeArgs()
uisky#14 yii/framework/web/actions/CInlineAction.php(47): CInlineAction->runWithParamsInternal()
uisky#15 yii/framework/web/CController.php(308): CInlineAction->runWithParams()
uisky#16 yii/framework/web/filters/CFilterChain.php(134): UsersController->runAction()
#17 yii/framework/web/CController.php(291): CFilterChain->run()
#18 yii/framework/web/CController.php(265): UsersController->runActionWithFilters()
#19 yii/framework/web/CWebApplication.php(282): UsersController->run()
#20 yii/framework/web/CWebApplication.php(141): CWebApplication->runController()
#21 yii/framework/base/CApplication.php(185): CWebApplication->processRequest()
#22 www/index.php(15): CWebApplication->run()

protected/models/User.php

@@ -305,27 +305,27 @@ public function getUpicDir() {
 	}
 
 	public function getUpicPath() {
-		if($this->upic[0] == 0) return "";
+		if($this->hasDefaultPicture()) return "";
 		return $this->upicDir . "/{$this->upicName}.jpg";
 	}
 
 	public function getUpicPathBig() {
-		if($this->upic[0] == 0) return "";
+		if($this->hasDefaultPicture()) return "";
 		return $this->upicDir . "/{$this->upicName}_big.jpg";
 	}
 
 	public function getUpicUrl() {
-		if($this->upic[0] == 0) return "/i/avatar_placeholder.png";
+		if($this->hasDefaultPicture()) return "/i/avatar_placeholder.png";
 		return "/i/upic/" . floor($this->id / 1000) . "/" . $this->upicName . ".jpg";
 	}
 
 	public function getUpicUrlBig() {
-		if($this->upic[0] == 0) return "";
+		if($this->hasDefaultPicture()) return "";
 		return "/i/upic/" . floor($this->id / 1000) . "/" . $this->upicName . "_big.jpg";
 	}
 
 	public function upicUnlink() {
-		if($this->upic[0] == 0) return false;
+		if($this->hasDefaultPicture()) return false;
 		@unlink($this->upicPath);
 		@unlink($this->upicPathBig);
 		$this->upic = array(0, 0, 0);
@@ -406,4 +406,8 @@ public function Notify($typ, $param1, $param2 = null, $param3 = null) {
 
 		return true;
 	}
+
+	protected function hasDefaultPicture(): bool {
+		return $this->upic === null || $this->upic[0] == 0;
+	}
 }