Fix the position of bound() in Container::instance() (#19207)

* fix:change the position of bound() in instance() to prevent that rebound() always fires incorrectly.More detail can see issues #19194

* failing test for change

* fix:rename the variable

Author: LeoYang90

src/Illuminate/Container/Container.php

@@ -357,14 +357,16 @@ public function instance($abstract, $instance)
     {
         $this->removeAbstractAlias($abstract);
 
+        $isBound = $this->bound($abstract);
+
         unset($this->aliases[$abstract]);
 
         // We'll check to determine if this type has been bound before, and if it has
         // we will fire the rebound callbacks registered with the container and it
         // can be updated with consuming classes that have gotten resolved here.
         $this->instances[$abstract] = $instance;
 
-        if ($this->bound($abstract)) {
+        if ($isBound) {
             $this->rebound($abstract);
         }
     }

tests/Container/ContainerTest.php

@@ -337,6 +337,20 @@ public function testReboundListenersOnInstances()
         $this->assertTrue($_SERVER['__test.rebind']);
     }
 
+    public function testReboundListenersOnInstancesOnlyFiresIfWasAlreadyBound()
+    {
+        $_SERVER['__test.rebind'] = false;
+
+        $container = new Container;
+        $container->rebinding('foo', function () {
+            $_SERVER['__test.rebind'] = true;
+        });
+        $container->instance('foo', function () {
+        });
+
+        $this->assertFalse($_SERVER['__test.rebind']);
+    }
+
     /**
      * @expectedException \Illuminate\Contracts\Container\BindingResolutionException
      * @expectedExceptionMessage Unresolvable dependency resolving [Parameter #0 [ <required> $first ]] in class Illuminate\Tests\Container\ContainerMixedPrimitiveStub