From 23fc6756f1894e1af35853eb2251f08d5b25cf30 Mon Sep 17 00:00:00 2001
From: Jay Berkenbilt <ejb@ql.org>
Date: Wed, 18 May 2022 10:45:54 -0400
Subject: Add QUtil::FileCloser to the public API

---
 include/qpdf/QUtil.hh | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

(limited to 'include')

diff --git a/include/qpdf/QUtil.hh b/include/qpdf/QUtil.hh
index 5d33b2a5..283db861 100644
--- a/include/qpdf/QUtil.hh
+++ b/include/qpdf/QUtil.hh
@@ -114,6 +114,33 @@ namespace QUtil
     QPDF_DLL
     FILE* fopen_wrapper(std::string const&, FILE*);
 
+    // This is a little class to help with automatic closing files.
+    // You can do something like
+    //
+    // QUtil::FileCloser fc(QUtil::safe_fopen(filename, "rb"));
+    //
+    // and then use fc.f to the file. Be sure to actually declare a
+    // variable of type FileCloser. Using it as a temporary won't work
+    // because it will close the file as soon as it goes out of scope.
+    class FileCloser
+    {
+      public:
+        FileCloser(FILE* f) :
+            f(f)
+        {
+        }
+
+        ~FileCloser()
+        {
+            if (f) {
+                fclose(f);
+                f = nullptr;
+            }
+        }
+
+        FILE* f;
+    };
+
     // Attempt to open the file read only and then close again
     QPDF_DLL
     bool file_can_be_opened(char const* filename);
-- 
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