Make sure we're aware of 3 different message domains

We have:

1. Source message domain.
2. Target message domain.
3. Result message domain (this is tied to 2 of the above).

This solution assumes we'd always like to use ICU format (result message
domain) if we use it in any of source or target catalogue.

Additionally because of default NULL values in source catalogue
(internal extractor design to set NULL for "target" when creating
messages catalogue from source collection) we have to check if desired
catalogue's messages field has a key (within requested domain) or not.
Using MessageCatalogue::defines() would return false for catalogue
without translation (NULL value).

Lastly - make sure internal messages field utilised result message
domain for consistency with result field.

php-translation#300

Catalogue/Operation/ReplaceOperation.php

@@ -11,6 +11,7 @@
 
 namespace Translation\Bundle\Catalogue\Operation;
 
+use Nyholm\NSA;
 use Symfony\Component\Translation\Catalogue\AbstractOperation;
 use Symfony\Component\Translation\MessageCatalogueInterface;
 use Symfony\Component\Translation\MetadataAwareInterface;
@@ -40,20 +41,28 @@ protected function processDomain($domain): void
 
         $intlDomain = $domain . '+intl-icu' /* MessageCatalogueInterface::INTL_DOMAIN_SUFFIX */;
 
+        $sourceMessages = NSA::getProperty($this->source, 'messages');
+        $targetMessages = NSA::getProperty($this->target, 'messages');
+
         foreach ($this->source->all($domain) as $id => $message) {
-            $messageDomain = $this->source->defines($id, $intlDomain) ? $intlDomain : $domain;
+            $sourceIdInIntl = array_key_exists($id, $sourceMessages[$intlDomain] ?? []);
+            $targetIdInIntl = array_key_exists($id, $targetMessages[$intlDomain] ?? []);
+
+            $sourceMessageDomain = $sourceIdInIntl ? $intlDomain : $domain;
+            $targetMessageDomain = $targetIdInIntl ? $intlDomain : $domain;
+            $resultMessageDomain = $sourceIdInIntl || $targetIdInIntl ? $intlDomain : $domain;
 
             if (!$this->target->has($id, $domain)) {
                 // No merge required
                 $translation = $message;
-                $this->messages[$domain]['new'][$id] = $message;
-                $resultMeta = $this->getMetadata($this->source, $messageDomain, $id);
+                $this->messages[$resultMessageDomain]['new'][$id] = $message;
+                $resultMeta = $this->getMetadata($this->source, $sourceMessageDomain, $id);
             } else {
                 // Merge required
-                $translation = $message ?? $this->target->get($id, $domain);
+                $translation = $message ?? $this->target->get($id, $targetMessageDomain);
                 $resultMeta = null;
-                $sourceMeta = $this->getMetadata($this->source, $messageDomain, $id);
-                $targetMeta = $this->getMetadata($this->target, $this->target->defines($id, $intlDomain) ? $intlDomain : $domain, $id);
+                $sourceMeta = $this->getMetadata($this->source, $sourceMessageDomain, $id);
+                $targetMeta = $this->getMetadata($this->target, $targetMessageDomain, $id);
                 if (\is_array($sourceMeta) && \is_array($targetMeta)) {
                     // We can only merge meta if both is an array
                     $resultMeta = $this->mergeMetadata($sourceMeta, $targetMeta);
@@ -65,11 +74,11 @@ protected function processDomain($domain): void
                 }
             }
 
-            $this->messages[$domain]['all'][$id] = $translation;
-            $this->result->add([$id => $translation], $messageDomain);
+            $this->messages[$resultMessageDomain]['all'][$id] = $translation;
+            $this->result->add([$id => $translation], $resultMessageDomain);
 
             if (!empty($resultMeta)) {
-                $this->result->setMetadata($id, $resultMeta, $messageDomain);
+                $this->result->setMetadata($id, $resultMeta, $resultMessageDomain);
             }
         }
 
@@ -80,14 +89,18 @@ protected function processDomain($domain): void
                 continue;
             }
 
-            $messageDomain = $this->target->defines($id, $intlDomain) ? $intlDomain : $domain;
-            $this->messages[$domain]['all'][$id] = $message;
-            $this->messages[$domain]['obsolete'][$id] = $message;
-            $this->result->add([$id => $message], $messageDomain);
+            $sourceIdInIntl = array_key_exists($id, $sourceMessages[$intlDomain] ?? []);
+            $targetIdInIntl = array_key_exists($id, $targetMessages[$intlDomain] ?? []);
+
+            $resultMessageDomain = $sourceIdInIntl || $targetIdInIntl ? $intlDomain : $domain;
+
+            $this->messages[$resultMessageDomain]['all'][$id] = $message;
+            $this->messages[$resultMessageDomain]['obsolete'][$id] = $message;
+            $this->result->add([$id => $message], $resultMessageDomain);
 
-            $resultMeta = $this->getMetadata($this->target, $messageDomain, $id);
+            $resultMeta = $this->getMetadata($this->target, $resultMessageDomain, $id);
             if (!empty($resultMeta)) {
-                $this->result->setMetadata($id, $resultMeta, $messageDomain);
+                $this->result->setMetadata($id, $resultMeta, $resultMessageDomain);
             }
         }
     }