Add test case of dangling ref not found until xref reconstruction

qpdf/qtest/dangling-refs.test

@@ -14,7 +14,7 @@ cleanup();
 
 my $td = new TestDriver('dangling-refs');
 
-my @dangling = (qw(minimal dangling-refs));
+my @dangling = (qw(minimal dangling-refs dangling-bad-xref));
 my $n_tests = 2 * scalar(@dangling);
 
 foreach my $f (@dangling)

qpdf/qtest/qpdf/dangling-bad-xref-dangling.out

@@ -0,0 +1,19 @@
+WARNING: dangling-bad-xref.pdf: file is damaged
+WARNING: dangling-bad-xref.pdf (object 7 0, offset 10000): expected n n obj
+WARNING: dangling-bad-xref.pdf: Attempting to reconstruct cross-reference table
+new object: 13 0 R
+all objects
+1 0 R
+2 0 R
+3 0 R
+4 0 R
+5 0 R
+6 0 R
+7 0 R
+8 0 R
+9 0 R
+10 0 R
+11 0 R
+12 0 R
+13 0 R
+test 53 done

qpdf/qtest/qpdf/dangling-bad-xref.pdf

@@ -0,0 +1,110 @@
+%PDF-1.3
+%¿÷¢þ
+%QDF-1.0
+
+1 0 obj
+<<
+  /Pages 2 0 R
+  /Type /Catalog
+  /Dangling 8 0 R
+  /AlsoDangling [
+    9 0 R
+    <<
+      /yes 2 0 R
+      /no 10 0 R
+      /nope 8 0 R
+    >>
+  ]
+>>
+endobj
+
+2 0 obj
+<<
+  /Count 1
+  /Kids [
+    3 0 R
+  ]
+  /Type /Pages
+>>
+endobj
+
+%% Page 1
+3 0 obj
+<<
+  /Contents 4 0 R
+  /MediaBox [
+    0
+    0
+    612
+    792
+  ]
+  /Parent 2 0 R
+  /Resources <<
+    /Font <<
+      /F1 6 0 R
+    >>
+    /ProcSet 7 0 R
+  >>
+  /Type /Page
+>>
+endobj
+
+%% Contents for page 1
+4 0 obj
+<<
+  /Length 5 0 R
+>>
+stream
+BT
+  /F1 24 Tf
+  72 720 Td
+  (Potato) Tj
+ET
+endstream
+endobj
+
+5 0 obj
+44
+endobj
+
+6 0 obj
+<<
+  /BaseFont /Helvetica
+  /Encoding /WinAnsiEncoding
+  /Name /F1
+  /Subtype /Type1
+  /Type /Font
+>>
+endobj
+
+7 0 obj
+[
+  /PDF
+  /Text
+]
+endobj
+
+11 0 obj
+[
+  12 0 R
+]
+endobj
+
+xref
+0 8
+0000000000 65535 f 
+0000000025 00000 n 
+0000000195 00000 n 
+0000000277 00000 n 
+0000000492 00000 n 
+0000000591 00000 n 
+0000000610 00000 n 
+0000010000 00000 n 
+trailer <<
+  /Root 1 0 R
+  /Size 8
+  /ID [<7141a6cf32de469328cf0f51982b5f89><7141a6cf32de469328cf0f51982b5f89>]
+>>
+startxref
+793
+%%EOF