[BUGFIX] Prevent different constants marker in TS parsing

Currently each time the TypoScript is parsed a new marker for constants,
which are replaces by their value, is generated. This prevents conditions
with replaced constants to be displayed as active. This patch ensures
markers are generated by constants values and therefore stay the same
in different requests.

Resolves: #78142
Related: #72413
Releases: master, 7.6
Change-Id: I4eea83908927ac48930abdd731e7412c04e529c1
Reviewed-on: https://review.typo3.org/51867
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>

typo3/sysext/core/Classes/TypoScript/ExtendedTemplateService.php

@@ -228,11 +228,6 @@ class ExtendedTemplateService extends TemplateService
      */
     public $clearList_setup_temp;
 
-    /**
-     * @var string
-     */
-    protected $Cmarker = '';
-
     /**
      * @var string
      */
@@ -281,7 +276,6 @@ class ExtendedTemplateService extends TemplateService
      */
     public function substituteConstants($all)
     {
-        $this->Cmarker = substr(md5(uniqid('', true)), 0, 6);
         return preg_replace_callback('/\\{\\$(.[^}]+)\\}/', [$this, 'substituteConstantsCallBack'], $all);
     }
 
@@ -294,12 +288,13 @@ public function substituteConstants($all)
      */
     public function substituteConstantsCallBack($matches)
     {
+        $marker = substr(md5($matches[0]), 0, 6);
         switch ($this->constantMode) {
             case 'const':
-                $ret_val = isset($this->flatSetup[$matches[1]]) && !is_array($this->flatSetup[$matches[1]]) ? '##' . $this->Cmarker . '_B##' . $matches[0] . '##' . $this->Cmarker . '_E##' : $matches[0];
+                $ret_val = isset($this->flatSetup[$matches[1]]) && !is_array($this->flatSetup[$matches[1]]) ? '##' . $marker . '_B##' . $matches[0] . '##' . $marker . '_E##' : $matches[0];
                 break;
             case 'subst':
-                $ret_val = isset($this->flatSetup[$matches[1]]) && !is_array($this->flatSetup[$matches[1]]) ? '##' . $this->Cmarker . '_B##' . $this->flatSetup[$matches[1]] . '##' . $this->Cmarker . '_E##' : $matches[0];
+                $ret_val = isset($this->flatSetup[$matches[1]]) && !is_array($this->flatSetup[$matches[1]]) ? '##' . $marker . '_B##' . $this->flatSetup[$matches[1]] . '##' . $marker . '_E##' : $matches[0];
                 break;
             case 'untouched':
                 $ret_val = $matches[0];
@@ -311,7 +306,7 @@ public function substituteConstantsCallBack($matches)
     }
 
     /**
-     * Subsitute markers
+     * Substitute markers
      *
      * @param string $all
      * @return string
@@ -321,10 +316,10 @@ public function substituteCMarkers($all)
         switch ($this->constantMode) {
             case 'const':
             case 'subst':
-                $all = str_replace(
-                    ['##' . $this->Cmarker . '_B##', '##' . $this->Cmarker . '_E##'],
-                    ['<strong style="color: green;">', '</strong>'],
-                    $all
+                $all = preg_replace(
+                    '/##[a-z0-9]{6}_B##((?:(?!##[a-z0-9]{6}_E##).)+)##[a-z0-9]{6}_E##/',
+                        '<strong style="color: green;">$1</strong>',
+                        $all
                 );
                 break;
             default:
@@ -804,9 +799,10 @@ public function ext_fixed_lgd($string, $chars)
     {
         if ($chars >= 4) {
             if (strlen($string) > $chars) {
-                if (strlen($string) > 24 && substr($string, 0, 12) == '##' . $this->Cmarker . '_B##') {
-                    return '##' . $this->Cmarker . '_B##' . GeneralUtility::fixed_lgd_cs(substr($string, 12, -12), ($chars - 3))
-                        . '##' . $this->Cmarker . '_E##';
+                if (strlen($string) > 24 && preg_match('/^##[a-z0-9]{6}_B##$/', substr($string, 0, 12))) {
+                    $string = GeneralUtility::fixed_lgd_cs(substr($string, 12, -12), ($chars - 3));
+                    $marker = substr(md5($string), 0, 6);
+                    return '##' . $marker . '_B##' . $string . '##' . $marker . '_E##';
                 } else {
                     return GeneralUtility::fixed_lgd_cs($string, $chars - 3);
                 }