Better recovery of bad stream start (fixes #104)

6 files changed, 65 insertions, 31 deletions

diff --git a/ChangeLog b/ChangeLog
index 66245656..f1291515 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,8 @@
 2017-07-29  Jay Berkenbilt  <ejb@ql.org>
 
+	* Improve handling of files where the "stream" keyword is not
+	followed by proper line terminators. Fixes #104.
+
 	* Fix content stream parsing to handle cases of structures within
 	the stream split across stream boundaries. Fixes #73.
 
diff --git a/libqpdf/QPDF.cc b/libqpdf/QPDF.cc
index 16641247..56555261 100644
--- a/libqpdf/QPDF.cc
+++ b/libqpdf/QPDF.cc
@@ -1117,6 +1117,11 @@ QPDF::readObject(PointerHolder<InputSource> input,
                 else
                 {
                     QTC::TC("qpdf", "QPDF stream without newline");
+                    if (! QUtil::is_space(ch))
+                    {
+                        QTC::TC("qpdf", "QPDF stream with non-space");
+                        input->unreadCh(ch);
+                    }
                     warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(),
                                  this->last_object_description,
                                  input->tell(),
diff --git a/qpdf/qpdf.testcov b/qpdf/qpdf.testcov
index c32d6ba5..d1ddd55d 100644
--- a/qpdf/qpdf.testcov
+++ b/qpdf/qpdf.testcov
@@ -283,3 +283,4 @@ QPDFWriter precheck stream 0
 QPDFWriter preserve unreferenced standard 0
 QPDFObjectHandle non-stream in parsecontent 0
 QPDFObjectHandle errors in parsecontent 0
+QPDF stream with non-space 0
diff --git a/qpdf/qtest/qpdf/stream-line-enders.out b/qpdf/qtest/qpdf/stream-line-enders.out
index b7a7513c..1932771f 100644
--- a/qpdf/qtest/qpdf/stream-line-enders.out
+++ b/qpdf/qtest/qpdf/stream-line-enders.out
@@ -1,3 +1,4 @@
-WARNING: stream-line-enders.pdf (object 5 0, file position 378): stream keyword followed by carriage return only
-WARNING: stream-line-enders.pdf (object 6 0, file position 437): stream keyword not followed by proper line terminator
+WARNING: stream-line-enders.pdf (object 5 0, file position 384): stream keyword followed by carriage return only
+WARNING: stream-line-enders.pdf (object 6 0, file position 443): stream keyword not followed by proper line terminator
+WARNING: stream-line-enders.pdf (object 7 0, file position 503): stream keyword not followed by proper line terminator
 qpdf: operation succeeded with warnings; resulting file may have some problems
diff --git a/qpdf/qtest/qpdf/stream-line-enders.pdf b/qpdf/qtest/qpdf/stream-line-enders.pdf
index e6238889..2e05caa1 100644
--- a/qpdf/qtest/qpdf/stream-line-enders.pdf
+++ b/qpdf/qtest/qpdf/stream-line-enders.pdf
@@ -7,7 +7,7 @@ endobj
 << /Count 1 /Kids [ 3 0 R ] /Type /Pages >>
 endobj
 3 0 obj
-<< /Contents [ 4 0 R 5 0 R 6 0 R ] /MediaBox [ 0 0 612 792 ] /Parent 2 0 R /Resources << /Font << /F1 7 0 R >> /ProcSet 8 0 R >> /Type /Page >>
+<< /Contents [ 4 0 R 5 0 R 6 0 R 7 0 R ] /MediaBox [ 0 0 612 792 ] /Parent 2 0 R /Resources << /Font << /F1 8 0 R >> /ProcSet 9 0 R >> /Type /Page >>
 endobj
 4 0 obj
 << /Length 14 >>
@@ -22,29 +22,35 @@ stream
72 720 Td
 endstream
 endobj
 6 0 obj
-<< /Length 15 >>
+<< /Length 12 >>
 stream (Potato) Tj
-ET
 endstream
 endobj
 7 0 obj
-<< /BaseFont /Helvetica /Encoding /WinAnsiEncoding /Name /F1 /Subtype /Type1 /Type /Font >>
+<< /Length 11 >>
+stream%comment
+ET
+endstream
 endobj
 8 0 obj
+<< /BaseFont /Helvetica /Encoding /WinAnsiEncoding /Name /F1 /Subtype /Type1 /Type /Font >>
+endobj
+9 0 obj
 [ /PDF /Text ]
 endobj
 xref
-0 9
+0 10
 0000000000 65535 f 
 0000000015 00000 n 
 0000000064 00000 n 
 0000000123 00000 n 
-0000000282 00000 n 
-0000000346 00000 n 
-0000000405 00000 n 
-0000000469 00000 n 
-0000000576 00000 n 
-trailer << /Root 1 0 R /Size 9 /ID [<08aa98c73f8a7262d77c8328772c3989><7b1f32865e2165debe277f27ee790092>] >>
+0000000288 00000 n 
+0000000352 00000 n 
+0000000411 00000 n 
+0000000472 00000 n 
+0000000532 00000 n 
+0000000639 00000 n 
+trailer << /Root 1 0 R /Size 10 /ID [<08aa98c73f8a7262d77c8328772c3989><5a35fde138b2e8251b9e079b560c0253>] >>
 startxref
-606
+669
 %%EOF
diff --git a/qpdf/qtest/qpdf/stream-line-enders.qdf b/qpdf/qtest/qpdf/stream-line-enders.qdf
index 33536028..aa14901e 100644
--- a/qpdf/qtest/qpdf/stream-line-enders.qdf
+++ b/qpdf/qtest/qpdf/stream-line-enders.qdf
@@ -29,6 +29,7 @@ endobj
     4 0 R
     6 0 R
     8 0 R
+    10 0 R
   ]
   /MediaBox [
     0
@@ -39,9 +40,9 @@ endobj
   /Parent 2 0 R
   /Resources <<
     /Font <<
-      /F1 10 0 R
+      /F1 12 0 R
     >>
-    /ProcSet 11 0 R
+    /ProcSet 13 0 R
   >>
   /Type /Page
 >>
@@ -86,17 +87,32 @@ endobj
 >>
 stream
 (Potato) Tj
-ET
 endstream
 endobj
 
 9 0 obj
-15
+12
 endobj
 
+%% Contents for page 1
 %% Original object ID: 7 0
 10 0 obj
 <<
+  /Length 11 0 R
+>>
+stream
+%comment
+ET
+endstream
+endobj
+
+11 0 obj
+12
+endobj
+
+%% Original object ID: 8 0
+12 0 obj
+<<
   /BaseFont /Helvetica
   /Encoding /WinAnsiEncoding
   /Name /F1
@@ -105,8 +121,8 @@ endobj
 >>
 endobj
 
-%% Original object ID: 8 0
-11 0 obj
+%% Original object ID: 9 0
+13 0 obj
 [
   /PDF
   /Text
@@ -114,24 +130,26 @@ endobj
 endobj
 
 xref
-0 12
+0 14
 0000000000 65535 f 
 0000000052 00000 n 
 0000000133 00000 n 
 0000000242 00000 n 
-0000000516 00000 n 
-0000000585 00000 n 
-0000000654 00000 n 
-0000000719 00000 n 
-0000000788 00000 n 
-0000000858 00000 n 
-0000000904 00000 n 
-0000001050 00000 n 
+0000000527 00000 n 
+0000000596 00000 n 
+0000000665 00000 n 
+0000000730 00000 n 
+0000000799 00000 n 
+0000000866 00000 n 
+0000000935 00000 n 
+0000001004 00000 n 
+0000001051 00000 n 
+0000001197 00000 n 
 trailer <<
   /Root 1 0 R
-  /Size 12
+  /Size 14
   /ID [<08aa98c73f8a7262d77c8328772c3989><31415926535897932384626433832795>]
 >>
 startxref
-1086
+1233
 %%EOF