Use realpath when concatenating files. (#1296)

- Fixes problems related to symlinks.

module/VuFindTheme/src/VuFindTheme/View/Helper/ConcatTrait.php

@@ -230,7 +230,10 @@ trait ConcatTrait
         }
         // Locate/create concatenated asset file
         $filename = md5($group['key']) . '.min.' . $this->getFileType();
-        $concatPath = $this->getResourceCacheDir() . $filename;
+        // Minifier uses realpath, so do that here too to make sure we're not
+        // pointing to a symlink. Otherwise the path converter won't find the correct
+        // shared directory part.
+        $concatPath = realpath($this->getResourceCacheDir()) . '/' . $filename;
         if (!file_exists($concatPath)) {
             $lockfile = "$concatPath.lock";
             $handle = fopen($lockfile, 'c+');
@@ -276,6 +279,7 @@ trait ConcatTrait
                 . $this->getResourceFilePath($item),
                 ThemeInfo::RETURN_ALL_DETAILS
             );
+            $details['path'] = realpath($details['path']);
             $data[] = $this->getMinifiedData($details, $concatPath);
         }
         // Separate each file's data with a new line so that e.g. a file