From c4d79d954978a6b3bf5b6c973fd73dc4e6b460eb Mon Sep 17 00:00:00 2001
From: JaiLuthra1 <luthrajaiji@gmail.com>
Date: Mon, 27 Jan 2020 14:18:20 +0530
Subject: [PATCH] pdftopdf- added handling of empty input

---
 filter/pdftopdf/pdftopdf.cc                | 11 +++++++++--
 filter/pdftopdf/qpdf_pdftopdf_processor.cc |  5 +++++
 2 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/filter/pdftopdf/pdftopdf.cc b/filter/pdftopdf/pdftopdf.cc
index e9702a66d..c49fe89d2 100644
--- a/filter/pdftopdf/pdftopdf.cc
+++ b/filter/pdftopdf/pdftopdf.cc
@@ -1107,6 +1107,7 @@ int main(int argc,char **argv)
        external utilities pdftocairo or Ghostscript, but these make
        the processing slower, especially due to extra piping of the
        data between processes. */
+    int empty = 0;
     int qpdf_flatten = 1;
     int pdftocairo_flatten = 0;
     int gs_flatten = 0;
@@ -1138,17 +1139,23 @@ int main(int argc,char **argv)
     if (argc==7) {
       if (!proc->loadFilename(argv[6],qpdf_flatten)) {
         ppdClose(ppd);
-        return 1;
+        empty = 1;
       }
     } else {
       tmpfile = copy_stdin_to_temp();
       if ((!tmpfile)||
 	  (!proc->loadFile(tmpfile,WillStayAlive,qpdf_flatten))) {
         ppdClose(ppd);
-        return 1;
+        empty = 1;
       }
     }
 
+    if(empty)
+    {
+      fprintf(stderr, "DEBUG: Input is empty, outputting empty file.\n");
+      return 0;
+    }
+
     /* If the input file contains a PDF form and we opted for not
        using QPDF for flattening the form, we pipe the PDF through
        pdftocairo or Ghostscript here */
diff --git a/filter/pdftopdf/qpdf_pdftopdf_processor.cc b/filter/pdftopdf/qpdf_pdftopdf_processor.cc
index a4baee876..769129f96 100644
--- a/filter/pdftopdf/qpdf_pdftopdf_processor.cc
+++ b/filter/pdftopdf/qpdf_pdftopdf_processor.cc
@@ -737,7 +737,12 @@ void QPDF_PDFTOPDF_Processor::emitFilename(const char *name) // {{{
     out.setExtraHeaderText(extraheader);
   }
   out.setPreserveEncryption(false);
+  std::vector<QPDFObjectHandle> pages=pdf->getAllPages();
+  int len=pages.size();
+  if (len)
   out.write();
+  else
+  fprintf(stderr, "DEBUG: Input is empty, outputting empty file.\n");
 }
 // }}}
 
-- 
2.47.2