Register style can be skipped when already registered

src/Spout/Writer/Common/Manager/Style/StyleManager.php

@@ -50,13 +50,11 @@ class StyleManager implements StyleManagerInterface
      * Typically, set "wrap text" if a cell contains a new line.
      *
      * @param Cell $cell
-     * @return Style
+     * @return Style|null The eventually updated style
      */
-    public function applyExtraStylesIfNeeded(Cell $cell)
+    public function applyExtraStylesIfNeeded(Cell $cell) : ?Style
     {
-        $updatedStyle = $this->applyWrapTextIfCellContainsNewLine($cell);
-
-        return $updatedStyle;
+        return $this->applyWrapTextIfCellContainsNewLine($cell);
     }
 
     /**
@@ -69,21 +67,23 @@ class StyleManager implements StyleManagerInterface
      *        on the Windows version of Excel...
      *
      * @param Cell $cell The cell the style should be applied to
-     * @return \Box\Spout\Common\Entity\Style\Style The eventually updated style
+     * @return Style|null The eventually updated style
      */
-    protected function applyWrapTextIfCellContainsNewLine(Cell $cell)
+    protected function applyWrapTextIfCellContainsNewLine(Cell $cell) : ?Style
     {
         $cellStyle = $cell->getStyle();
 
         // if the "wrap text" option is already set, no-op
         if ($cellStyle->hasSetWrapText()) {
-            return $cellStyle;
+            return null;
         }
 
         if ($cell->isString() && \strpos($cell->getValue(), "\n") !== false) {
             $cellStyle->setShouldWrapText();
+
+            return $cellStyle;
         }
 
-        return $cellStyle;
+        return null;
     }
 }

src/Spout/Writer/Common/Manager/Style/StyleManagerInterface.php

@@ -24,7 +24,7 @@ interface StyleManagerInterface
      * Typically, set "wrap text" if a cell contains a new line.
      *
      * @param Cell $cell
-     * @return Style The updated style
+     * @return Style|null The eventually updated style
      */
-    public function applyExtraStylesIfNeeded(Cell $cell);
+    public function applyExtraStylesIfNeeded(Cell $cell) : ?Style;
 }

src/Spout/Writer/Common/Manager/Style/StyleRegistry.php

@@ -38,7 +38,7 @@ class StyleRegistry
 
         if (!$this->hasSerializedStyleAlreadyBeenRegistered($serializedStyle)) {
             $nextStyleId = \count($this->serializedStyleToStyleIdMappingTable);
-            $style->setId($nextStyleId);
+            $style->register($nextStyleId);
 
             $this->serializedStyleToStyleIdMappingTable[$serializedStyle] = $nextStyleId;
             $this->styleIdToStyleMappingTable[$nextStyleId] = $style;
@@ -112,9 +112,10 @@ class StyleRegistry
      */
     public function serialize(Style $style)
     {
-        // In order to be able to properly compare style, set static ID value
+        // In order to be able to properly compare style, set static ID value and reset registration
         $currentId = $style->getId();
         $style->setId(0);
+        $style->setRegistered(false);
 
         $serializedStyle = \serialize($style);