octoleo/qpdf
2
1
Fork 0
mirror of https://github.com/qpdf/qpdf.git synced 2024-12-22 10:58:58 +00:00
Code Issues Releases Wiki Activity

Add additional sanity check during xref reconstruction

Browse Source 
Check that xref table is not empty after recovery. Empty xref tables
disable other sanity checks.
This commit is contained in:
m-holger 2024-07-09 16:53:33 +01:00
parent 7445e0ac1e
commit 2e378d920d
2 changed files with 6 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
libqpdf/QPDF.cc
View File

@ -641,6 +641,11 @@ QPDF::reconstruct_xref(QPDFExc& e)
throw damagedPDF("", 0, "unable to find trailer dictionary while recovering damaged file"); throw damagedPDF("", 0, "unable to find trailer dictionary while recovering damaged file");
} }
if (m->xref_table.empty()) {
// We cannot check for an empty xref table in parse because empty tables are valid when
// creating QPDF objects from JSON.
throw damagedPDF("", 0, "unable to find objects while recovering damaged file");
}
// We could iterate through the objects looking for streams and try to find objects inside of // We could iterate through the objects looking for streams and try to find objects inside of
// them, but it's probably not worth the trouble. Acrobat can't recover files with any errors // them, but it's probably not worth the trouble. Acrobat can't recover files with any errors

2
qpdf/qtest/qpdf/issue-147.out
View File

@ -4,4 +4,4 @@ WARNING: issue-147.pdf: can't find startxref
WARNING: issue-147.pdf: Attempting to reconstruct cross-reference table WARNING: issue-147.pdf: Attempting to reconstruct cross-reference table
WARNING: issue-147.pdf (trailer, offset 9): expected dictionary key but found non-name object; inserting key /QPDFFake1 WARNING: issue-147.pdf (trailer, offset 9): expected dictionary key but found non-name object; inserting key /QPDFFake1
WARNING: issue-147.pdf: ignoring object with impossibly large id 62 WARNING: issue-147.pdf: ignoring object with impossibly large id 62
qpdf: issue-147.pdf: unable to find /Root dictionary qpdf: issue-147.pdf: unable to find objects while recovering damaged file