if the PDF is empty, do not convert

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@21218 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5/Document/PDFDocument.py

@@ -126,6 +126,8 @@ class PDFDocument(Image, ConversionCacheMixin):
     """
       Convert the PDF text content to text with pdftotext
     """
+    if not self.data:
+      return ''
     tmp = tempfile.NamedTemporaryFile()
     tmp.write(_unpackData(self.data))
     tmp.seek(0)
@@ -144,6 +146,8 @@ class PDFDocument(Image, ConversionCacheMixin):
     NOTE: XXX check that command exists and was executed
     successfully
     """
+    if not self.data:
+      return ''
     tmp = tempfile.NamedTemporaryFile()
     tmp.write(_unpackData(self.data))
     tmp.seek(0)