Custom logo HTML (#4369)

* Custom logo HTML
Add option for custom HTML logo/title in the main Web UI view.
Can potentially be different per user.
#fix https://github.com/FreshRSS/FreshRSS/pull/3830/files#r850472247

* logo_html in main config
With new `./data/config.custom.php` to provide custom values before install

* Docker documentation

* whitespace

* Auto relax CSP to allow images for HTML logo

* Documentation

6 files changed, 32 insertions, 2 deletions

diff --git a/app/Controllers/statsController.php b/app/Controllers/statsController.php
index be29bfac4..1798ee3cf 100644
--- a/app/Controllers/statsController.php
+++ b/app/Controllers/statsController.php
@@ -17,6 +17,7 @@ class FreshRSS_stats_Controller extends FreshRSS_ActionController {
 
 		$this->_csp([
 			'default-src' => "'self'",
+			'img-src' => '* data:',
 			'style-src' => "'self' 'unsafe-inline'",
 		]);
 
diff --git a/app/FreshRSS.php b/app/FreshRSS.php
index dc5ed0999..602c46658 100644
--- a/app/FreshRSS.php
+++ b/app/FreshRSS.php
@@ -32,6 +32,14 @@ class FreshRSS extends Minz_FrontController {
 			die($message);
 		}
 
+		if (FreshRSS_Context::$system_conf->logo_html != '') {
+			// Relax Content Security Policy to allow external images if a custom logo HTML is used
+			Minz_ActionController::_defaultCsp([
+				'default-src' => "'self'",
+				'img-src' => '* data:',
+			]);
+		}
+
 		// Load list of extensions and enable the "system" ones.
 		Minz_ExtensionManager::init();
 
diff --git a/app/Models/SystemConfiguration.php b/app/Models/SystemConfiguration.php
index 3170a4180..ec5960c0e 100644
--- a/app/Models/SystemConfiguration.php
+++ b/app/Models/SystemConfiguration.php
@@ -17,6 +17,7 @@
  * @property-read string $http_auth_auto_register_email_field
  * @property-read string $language
  * @property array<string,int> $limits
+ * @property-read string $logo_html
  * @property-read string $meta_description
  * @property-read bool $pubsubhubbub_enabled
  * @property-read string $salt
diff --git a/app/install.php b/app/install.php
index 9186404c1..b0363efbc 100644
--- a/app/install.php
+++ b/app/install.php
@@ -145,6 +145,14 @@ function saveStep2() {
 			$config_array['auth_type'] = Minz_Session::param('auth_type');
 		}
 
+		$customConfigPath = DATA_PATH . '/config.custom.php';
+		if (file_exists($customConfigPath)) {
+			$customConfig = include($customConfigPath);
+			if (is_array($customConfig)) {
+				$config_array = array_merge($customConfig, $config_array);
+			}
+		}
+
 		@unlink(DATA_PATH . '/config.php');	//To avoid access-rights problems
 		file_put_contents(DATA_PATH . '/config.php', "<?php\n return " . var_export($config_array, true) . ";\n");
 
diff --git a/app/layout/header.phtml b/app/layout/header.phtml
index b5a9b662c..94a83894e 100644
--- a/app/layout/header.phtml
+++ b/app/layout/header.phtml
@@ -1,7 +1,13 @@
 <header class="header">
 	<div class="item title">
 		<a href="<?= _url('index', 'index') ?>">
-			<img class="logo" src="<?= _i('FreshRSS-logo', true) ?>" alt="" />
+			<?php if (FreshRSS_Context::$system_conf->logo_html == '') { ?>
+				<img class="logo" src="<?= _i('FreshRSS-logo', true) ?>" alt="FreshRSS" />
+			<?php
+				} else {
+					echo FreshRSS_Context::$system_conf->logo_html;
+				}
+			?>
 		</a>
 	</div>
 
diff --git a/app/layout/simple.phtml b/app/layout/simple.phtml
index 1858c3fed..b4d3530bc 100644
--- a/app/layout/simple.phtml
+++ b/app/layout/simple.phtml
@@ -30,7 +30,13 @@
 	<div class="header">
 		<div class="item title">
 			<a href="<?= _url('index', 'index') ?>">
-				<img class="logo" src="<?= _i('FreshRSS-logo', true) ?>" alt="" />
+				<?php if (FreshRSS_Context::$system_conf->logo_html == '') { ?>
+					<img class="logo" src="<?= _i('FreshRSS-logo', true) ?>" alt="FreshRSS" />
+				<?php
+					} else {
+						echo FreshRSS_Context::$system_conf->logo_html;
+					}
+				?>
 			</a>
 		</div>