bug #906 Fix compat with old composer versions (nicolas-grekas)

This PR was merged into the 1.x branch.

Discussion
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Fix compat with old composer versions

Fix #893

Commits
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01c41aa Fix compat with old composer versions

Author: nicolas-grekas

src/Command/UnpackCommand.php

@@ -110,9 +110,14 @@ protected function execute(InputInterface $input, OutputInterface $output)
             ->setDumpAutoloader(false)
             ->setIgnorePlatformRequirements(true)
             ->setUpdate(true)
-            ->setUpdateAllowList(['php'])
         ;
 
+        if (method_exists($installer, 'setUpdateAllowList')) {
+            $installer->setUpdateAllowList(['php']);
+        } else {
+            $installer->setUpdateWhiteList(['php']);
+        }
+
         if (method_exists($composer->getEventDispatcher(), 'setRunScripts')) {
             $composer->getEventDispatcher()->setRunScripts(false);
         } else {

src/Flex.php

@@ -1013,8 +1013,10 @@ private function reinstall(Event $event, bool $update)
             $composer->getAutoloadGenerator()
         );
 
-        if (!$update) {
+        if (!$update && method_exists($installer, 'setUpdateAllowList')) {
             $installer->setUpdateAllowList(['php']);
+        } elseif (!$update) {
+            $installer->setUpdateWhiteList(['php']);
         }
 
         if (method_exists($installer, 'setSkipSuggest')) {