Prevent endless loops during Page->getText() because of faulty recursionStack

src/Smalot/PdfParser/PDFObject.php

@@ -437,8 +437,6 @@ public function getText(?Page $page = null): string
             $result .= $text;
         }
 
-        array_pop(self::$recursionStack);
-
         return $result.' ';
     }
 

src/Smalot/PdfParser/Page.php

@@ -210,7 +210,15 @@ public function getText(self $page = null): string
                 $contents = new PDFObject($this->document, $header, $new_content, $this->config);
             }
 
-            return $contents->getText($this);
+            /*
+             * Elements referecing eachother on the same page can cause endless loops during text parsing.
+             * To combat this we keep a recursionStack containing already parsed elements on the page.
+             * The stack is only emptied here after getting text from a page.
+             */
+            $contentsText = $contents->getText($this);
+            PDFObject::$recursionStack = [];
+
+            return $contentsText;
         }
 
         return '';

tests/Integration/PageTest.php

@@ -141,6 +141,38 @@ public function testGetText()
         $this->assertStringContainsString('Verdana', $text);
     }
 
+    /**
+     * @see https://github.com/smalot/pdfparser/pull/457
+     */
+    public function testGetTextPullRequest457()
+    {
+        // Document with text.
+        $filename = $this->rootDir.'/samples/bugs/PullRequest457.pdf';
+        $parser = $this->getParserInstance();
+        $document = $parser->parseFile($filename);
+        $pages = $document->getPages();
+        $page = $pages[0];
+        $text = $page->getText();
+
+        $this->assertTrue(1000 < \strlen($text));
+        $this->assertStringContainsString('SUPER', $text);
+        $this->assertStringContainsString('VOORDEEL', $text);
+        $this->assertStringContainsString('KRANT', $text);
+        $this->assertStringContainsString('DINSDAG', $text);
+        $this->assertStringContainsString('Snelfilterkoffie', $text);
+        $this->assertStringContainsString('AardappelenZak', $text);
+        $this->assertStringContainsString('ALL', $text);
+
+        // Force garbage collection to not interfere with other tests.
+        unset($filename);
+        unset($parser);
+        unset($document);
+        unset($pages);
+        unset($page);
+        unset($text);
+        gc_collect_cycles();
+    }
+
     public function testExtractRawData()
     {
         // Document with text.