fix: prevent deletion of files outside the temporary directory and improve test coverage

src/Knp/Snappy/AbstractGenerator.php

@@ -316,6 +316,15 @@ public function getCommand($input, $output, array $options = [])
     public function removeTemporaryFiles()
     {
         foreach ($this->temporaryFiles as $file) {
+            $filePath = \realpath($file);
+            $temporaryFolderPath = \realpath($this->getTemporaryFolder());
+            if (
+                !$filePath
+                || !$temporaryFolderPath
+                || !\str_starts_with($filePath, $temporaryFolderPath)
+            ) {
+                continue;
+            }
             $this->unlink($file);
         }
     }
@@ -328,7 +337,7 @@ public function removeTemporaryFiles()
     public function getTemporaryFolder()
     {
         if ($this->temporaryFolder === null) {
-            return \sys_get_temp_dir();
+            $this->temporaryFolder = \sys_get_temp_dir();
         }
 
         return $this->temporaryFolder;
@@ -501,10 +510,9 @@ protected function createTemporaryFile($content = null, $extension = null)
 
         if (null !== $content) {
             \file_put_contents($filename, $content);
+            $this->temporaryFiles[] = $filename;
         }
 
-        $this->temporaryFiles[] = $filename;
-
         return $filename;
     }
 

tests/Knp/Snappy/AbstractGeneratorTest.php

@@ -848,6 +848,26 @@ public function dataForIsAssociativeArray(): array
         ];
     }
 
+    public function testAvoidingDeletingFileOutsideTemporaryDirectory(): void
+    {
+        $generator = $this->getMockBuilder(AbstractGenerator::class)
+            ->setMethods([
+                'configure',
+                'unlink',
+            ])
+            ->setConstructorArgs(['the_binary'])
+            ->getMock()
+        ;
+
+        $generator
+            ->expects($this->never())
+            ->method('unlink')
+        ;
+
+        $remove = new ReflectionMethod($generator, 'removeTemporaryFiles');
+        $remove->invoke($generator);
+    }
+
     public function testCleanupEmptyTemporaryFiles(): void
     {
         $generator = $this->getMockBuilder(AbstractGenerator::class)
@@ -860,21 +880,21 @@ public function testCleanupEmptyTemporaryFiles(): void
         ;
 
         $generator
-            ->expects($this->once())
+            ->expects($this->never())
             ->method('unlink')
         ;
 
         $create = new ReflectionMethod($generator, 'createTemporaryFile');
         $create->invoke($generator, null, null);
 
         $files = new ReflectionProperty($generator, 'temporaryFiles');
-        $this->assertCount(1, $files->getValue($generator));
+        $this->assertCount(0, $files->getValue($generator));
 
         $remove = new ReflectionMethod($generator, 'removeTemporaryFiles');
         $remove->invoke($generator);
     }
 
-    public function testleanupTemporaryFiles(): void
+    public function testCleanupTemporaryFiles(): void
     {
         $generator = $this->getMockBuilder(AbstractGenerator::class)
             ->setMethods([