fix(locale-links): Fix locale handling when fetching link resources

CHANGELOG.md

@@ -5,6 +5,10 @@ This project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased](https://github.com/contentful/contentful.php/compare/4.0.1...HEAD)
 
+### Fixed
+
+* Resolving links from an entry using non-default locale caused the SDK to wrongly assume the `locale=*`. Now this is fixed, and the  entry will use either its current locale, if set, or the the `locale=*` if no locales are currently configured.
+
 ## [4.0.1](https://github.com/contentful/contentful.php/tree/4.0.1) (2018-11-08)
 
 ### Fixed

src/Resource/Entry.php

@@ -337,11 +337,12 @@ private function getUnresolvedField(Field $field, string $locale = \null)
      */
     private function resolveFieldLinks($field, string $locale = \null)
     {
-        // If there is no locale, it means the current entry
-        // has been requested using the * locale, so we explicitly set it
-        // to avoid issues with the resource pool
+        // If no locale is set, to resolve links we use either the special "*" locale,
+        // or the default one, depending whether this entry was built using a locale or not
         if (\null === $locale) {
-            $locale = '*';
+            $locale = \null === $this->sys->getLocale()
+                ? '*'
+                : $this->getLocale();
         }
 
         if ($field instanceof Link) {

src/Resource/LocalizedResource.php

@@ -71,6 +71,8 @@ public function setLocale($locale)
 
     /**
      * The locale code for the currently set locale.
+     * It will be either the default locale if the resource was fetched using "locale=*",
+     * or the one that was used in the API request.
      *
      * @return string
      */