Adding extra check if def macros are not actually present in the source

jsm.inc.php

@@ -254,9 +254,8 @@ class JSM
   {
     if(strpos($txt, '/*') === false)
       return $txt;
-    $regex = '~/\*.*?\*/~s';
     $txt = preg_replace_callback(
-      $regex, 
+      '~/\*.*?\*/~s',
       //preserve the new lines for better error reporting
       function($m) { return str_repeat("\n", substr_count($m[0], "\n")); },
       $txt);
@@ -266,7 +265,11 @@ class JSM
   private static function _removeLineComments(string $txt) : string
   {
     //TODO: it's not robust enough, note a hack for URL addresses
-    $txt = preg_replace("~\s*(?<!:)//.*~", "\n", $txt);
+    $txt = preg_replace_callback(
+      '~\s*(?<!:)//.*~', 
+      //preserve the new lines for better error reporting
+      function($m) { return str_repeat("\n", substr_count($m[0], "\n")); },
+      $txt);
     return $txt;
   }
 
@@ -520,7 +523,12 @@ class JSM
 
   private function _extractScriptDefs(string $file, string $txt) : string
   {
-    if(strpos($txt, 'def') === false)
+    $strpos = strpos($txt, 'def');
+    if($strpos === false)
+      return $txt;
+
+    //let's extra check if newline symbols preceed 'def'
+    if($strpos > 0 && !($txt[$strpos-1] === "\n" || $txt[$strpos-1] === "\r"))
       return $txt;
 
     //NOTE: make it more robust