Regression test for a crash related to str_increment

Author: ondrejmirtes

tests/PHPStan/Analyser/nsrt/bug-13481.php

@@ -0,0 +1,23 @@
+<?php
+
+namespace bug13481;
+
+use function PHPStan\Testing\assertType;
+use function str_increment;
+
+function bug13481() {
+	$s = 'ab c1';
+	assertType("*NEVER*", str_increment($s));
+
+	++$s;
+	assertType("*NEVER*", $s);
+}
+
+function bug13481b() {
+	$s = '%';
+	assertType("*NEVER*", str_increment($s));
+
+	++$s;
+	assertType("*NEVER*", $s);
+}
+