[Process] Ignore invalid env var names

Author: nicolas-grekas

Process.php

@@ -331,7 +331,7 @@ public function start(?callable $callback = null, array $env = [])
 
         $envPairs = [];
         foreach ($env as $k => $v) {
-            if (false !== $v && false === \in_array($k, ['argc', 'argv', 'ARGC', 'ARGV'], true)) {
+            if (false !== $v && !\in_array($k = (string) $k, ['', 'argc', 'argv', 'ARGC', 'ARGV'], true) && !str_contains($k, '=') && !str_contains($k, "\0")) {
                 $envPairs[] = $k.'='.$v;
             }
         }

Tests/ProcessTest.php

@@ -1568,6 +1568,46 @@ public function testEnvArgument()
         $this->assertSame($env, $p->getEnv());
     }
 
+    public function testEnvVarNamesCastToString()
+    {
+        $process = $this->getProcess('echo hello');
+        $process->setEnv([123 => 'value']);
+
+        $process->run();
+
+        $this->assertSame('hello'.\PHP_EOL, $process->getOutput());
+    }
+
+    public function testEnvVarNamesWithEqualsSigns()
+    {
+        $process = $this->getProcess('echo hello');
+        $process->setEnv(['VAR=NAME' => 'value']);
+
+        $process->run();
+
+        $this->assertSame('hello'.\PHP_EOL, $process->getOutput());
+    }
+
+    public function testEnvVarNamesWithNullBytes()
+    {
+        $process = $this->getProcess('echo hello');
+        $process->setEnv(["VAR\0NAME" => 'value']);
+
+        $process->run();
+
+        $this->assertSame('hello'.\PHP_EOL, $process->getOutput());
+    }
+
+    public function testEnvVarNamesEmpty()
+    {
+        $process = $this->getProcess('echo hello');
+        $process->setEnv(['' => 'value']);
+
+        $process->run();
+
+        $this->assertSame('hello'.\PHP_EOL, $process->getOutput());
+    }
+
     public function testWaitStoppedDeadProcess()
     {
         $process = $this->getProcess(self::$phpBin.' '.__DIR__.'/ErrorProcessInitiator.php -e '.self::$phpBin);