ISLANDORA-356: Warnings issued when MIMEClass is trying to determine the MIME type of a file via non-existent system files.

MimeClass.inc

@@ -301,6 +301,7 @@ class MimeClass {
    */
   private function system_mime_type_extensions() {
     $out = array();
+    if (file_exists($this->etc_mime_types)) {
       $file = fopen($this->etc_mime_types, 'r');
       while (($line = fgets($file)) !== FALSE) {
         $line = trim(preg_replace('/#.*/', '', $line));
@@ -316,6 +317,7 @@ class MimeClass {
         // We take the first ext from the line if many are present.
       }
       fclose($file);
+    }
     return $out;
   }
 
@@ -328,6 +330,7 @@ class MimeClass {
    */
   private function system_extension_mime_types() {
     $out = array();
+    if (file_exists($this->etc_mime_types)) {
       $file = fopen($this->etc_mime_types, 'r');
       while (($line = fgets($file)) !== FALSE) {
         $line = trim(preg_replace('/#.*/', '', $line));
@@ -342,6 +345,7 @@ class MimeClass {
           $out[$part] = $type;
       }
       fclose($file);
+    }
     return $out;
   }