add merge-replace config

README.md

@@ -66,6 +66,7 @@ Usage
             "merge-dev": true,
             "merge-extra": false,
             "merge-extra-deep": false,
+            "merge-replace": true,
             "merge-scripts": false
         }
     }
@@ -180,6 +181,11 @@ they are processed by Composer.
 Note that `merge-plugin` sections are excluded from the merge process, but are
 always processed by the plugin unless [recursion](#recurse) is disabled.
 
+### merge-replace
+
+By default, the `replace` section of included files are merged.
+A `"merge-replace": false` setting will disable this behavior.
+
 ### merge-scripts
 
 A `"merge-scripts": true` setting enables merging the contents of the

src/ExtraPackage.php

@@ -171,7 +171,11 @@ public function mergeInto(RootPackageInterface $root, PluginState $state)
         $this->mergeRequires('require', $root, $state);
 
         $this->mergePackageLinks('conflict', $root);
-        $this->mergePackageLinks('replace', $root);
+
+        if ($state->shouldMergeReplace()) {
+            $this->mergePackageLinks('replace', $root);
+        }
+
         $this->mergePackageLinks('provide', $root);
 
         $this->mergeSuggests($root);

src/PluginState.php

@@ -98,6 +98,13 @@ class PluginState
      */
     protected $mergeExtraDeep = false;
 
+    /**
+     * Whether to merge the replace section.
+     *
+     * @var bool $mergeReplace
+     */
+    protected $mergeReplace = true;
+
     /**
      * Whether to merge the scripts section.
      *
@@ -160,6 +167,7 @@ public function loadSettings()
                 'merge-dev' => true,
                 'merge-extra' => false,
                 'merge-extra-deep' => false,
+                'merge-replace' => true,
                 'merge-scripts' => false,
             ],
             $extra['merge-plugin'] ?? []
@@ -175,6 +183,7 @@ public function loadSettings()
         $this->mergeDev = (bool)$config['merge-dev'];
         $this->mergeExtra = (bool)$config['merge-extra'];
         $this->mergeExtraDeep = (bool)$config['merge-extra-deep'];
+        $this->mergeReplace = (bool)$config['merge-replace'];
         $this->mergeScripts = (bool)$config['merge-scripts'];
     }
 
@@ -386,6 +395,18 @@ public function shouldMergeExtraDeep()
         return $this->mergeExtraDeep;
     }
 
+    /**
+     * Should the replace section be merged?
+     *
+     * By default, the replace section is merged.
+     *
+     * @return bool
+     */
+    public function shouldMergeReplace()
+    {
+        return $this->mergeReplace;
+    }
+
     /**
      * Should the scripts section be merged?
      *