Add regression test for array self-append

Author: herndlm

tests/PHPStan/Analyser/AnalyserIntegrationTest.php

@@ -981,6 +981,12 @@ public function testArrayUnion(): void
 		$this->assertNoErrors($errors);
 	}
 
+	public function testBug6948(): void
+	{
+		$errors = $this->runAnalyse(__DIR__ . '/data/bug-6948.php');
+		$this->assertNoErrors($errors);
+	}
+
 	public function testBug7963(): void
 	{
 		$errors = $this->runAnalyse(__DIR__ . '/data/bug-7963.php');

tests/PHPStan/Analyser/data/bug-6948.php

@@ -0,0 +1,64 @@
+<?php declare(strict_types = 1);
+
+namespace Bug6948;
+
+$row = [1];
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}
+if (rand()) {
+	$row[] = $row;
+}