MDL-58746 core: Add environment check for finfo

admin/environment.xml

@@ -2043,6 +2043,11 @@
           <ON_CHECK message="incompleteunicodesupport" />
         </FEEDBACK>
       </CUSTOM_CHECK>
+      <CUSTOM_CHECK file="lib/upgradelib.php" function="check_finfo" level="required">
+        <FEEDBACK>
+          <ON_ERROR message="finforequired" />
+        </FEEDBACK>
+      </CUSTOM_CHECK>
     </CUSTOM_CHECKS>
   </MOODLE>
 </COMPATIBILITY_MATRIX>

lang/en/admin.php

@@ -599,6 +599,7 @@
 It is recommended to install local copy of free GeoLite City database from MaxMind.<br />
 IP address location is displayed on simple map or using Google Maps. Please note that you need to have a Google account and apply for free Google Maps API key to enable interactive maps.';
 $string['iplookupmaxmindnote'] = 'This product includes GeoLite data created by MaxMind, available from <a href="http://www.maxmind.com/">http://www.maxmind.com/</a>.';
+$string['finforequired'] = 'The finfo PHP extension is now required by Moodle, in order to improve mimetype decoding.';
 $string['keeptagnamecase'] = 'Keep tag name casing';
 $string['lang'] = 'Default language';
 $string['langcache'] = 'Cache language menu';

lib/upgradelib.php

@@ -2479,3 +2479,20 @@ function check_libcurl_version(environment_results $result) {
 
     return null;
 }
+
+/**
+ * Check if the finfo class is present.
+ *
+ * @param environment_results $result object to update, if relevant.
+ * @return environment_results|null updated results or null.
+ */
+function check_finfo(environment_results $result) {
+    if (!class_exists('finfo')) {
+        $result->setInfo('finfo extension not enabled');
+        $result->setStatus(false);
+
+        return $result;
+    }
+
+    return null;
+}