bugfix: allow a maximum key length of 65534 in PSR-16 decorator

To avoid having PCRE compilation error regarding `number too big`, we have to limit the maximum key length of the decorator. This will allow us to keep the performance benefits of `preg_match` while still allowing more than the initial 64 characters limit.

Signed-off-by: Maximilian Bösing <2189546+boesing@users.noreply.github.com>

src/Psr/SimpleCache/SimpleCacheDecorator.php

@@ -25,6 +25,7 @@
 use function is_object;
 use function is_scalar;
 use function is_string;
+use function min;
 use function preg_match;
 use function preg_quote;
 use function sprintf;
@@ -472,6 +473,6 @@ private function memoizeMaximumKeyLengthCapability(StorageInterface $storage, Ca
             ));
         }
 
-        $this->maximumKeyLength = $maximumKeyLength;
+        $this->maximumKeyLength = min($maximumKeyLength, self::PCRE_MAXIMUM_QUANTIFIER_LENGTH - 1);
     }
 }

test/Psr/SimpleCache/SimpleCacheDecoratorTest.php

@@ -20,6 +20,7 @@
 
 use function array_keys;
 use function iterator_to_array;
+use function preg_match;
 use function sprintf;
 use function str_repeat;
 
@@ -1152,4 +1153,18 @@ public function testWillUsePcreMaximumQuantifierLengthIfAdapterAllowsMoreThanTha
         ));
         $decorator->has($key);
     }
+
+    public function testPcreMaximumQuantifierLengthWontResultInCompilationError(): void
+    {
+        self::assertEquals(
+            0,
+            preg_match(
+                sprintf(
+                    '/^.{%d,}$/',
+                    SimpleCacheDecorator::PCRE_MAXIMUM_QUANTIFIER_LENGTH
+                ),
+                ''
+            )
+        );
+    }
 }