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| author | Paul Gardiner <paul.gardiner@artifex.com> | 2018-07-16 13:33:59 +0100 |
|---|---|---|
| committer | Paul Gardiner <paul.gardiner@artifex.com> | 2018-07-17 14:57:57 +0100 |
| commit | 709b4b95e1b30a62511234773fb53f75a40279f3 (patch) | |
| tree | 8af592f96e85a461470ab94c20a40d20afffb618 | |
| parent | 3d22bf8ba1c824f6722be63d9b5109fce56e076c (diff) | |
| download | mupdf-709b4b95e1b30a62511234773fb53f75a40279f3.tar.xz | |
Disallow incremental updating for documents that have hybrid xrefs
Alter pdf_can_be_saved_incrementally to return false when a hybrid xref
file has been opened. This doesn't enforce the behaviour, but will ensure
it for apps that determine their behaviour via this test function.
Once changes have been saved to such a file, it is no longer hybrid and so
further saving steps can use incremental updates.
This change was made because we were previously unable to sign hybrid xref
documents in a way that was satisfactory to Adobe Reader. Adobe Reader
reorganises hybrid xref files, thus invalidating any signature.
| -rw-r--r-- | include/mupdf/pdf/document.h | 1 | ||||
| -rw-r--r-- | source/pdf/pdf-write.c | 5 | ||||
| -rw-r--r-- | source/pdf/pdf-xref.c | 2 |
3 files changed, 8 insertions, 0 deletions
diff --git a/include/mupdf/pdf/document.h b/include/mupdf/pdf/document.h index f73cf5f3..24e3aaed 100644 --- a/include/mupdf/pdf/document.h +++ b/include/mupdf/pdf/document.h @@ -635,6 +635,7 @@ struct pdf_document_s int *xref_index; int freeze_updates; int has_xref_streams; + int has_old_style_xrefs; int rev_page_count; pdf_rev_page_map *rev_page_map; diff --git a/source/pdf/pdf-write.c b/source/pdf/pdf-write.c index 53a63cfc..26fcd9d1 100644 --- a/source/pdf/pdf-write.c +++ b/source/pdf/pdf-write.c @@ -2177,6 +2177,8 @@ static void writexrefstream(fz_context *ctx, pdf_document *doc, pdf_write_state { fz_rethrow(ctx); } + + doc->has_old_style_xrefs = 0; } static void @@ -2865,6 +2867,9 @@ int pdf_can_be_saved_incrementally(fz_context *ctx, pdf_document *doc) return 0; if (doc->crypt != NULL) return 0; + if (doc->has_xref_streams && doc->has_old_style_xrefs) + return 0; + return 1; } diff --git a/source/pdf/pdf-xref.c b/source/pdf/pdf-xref.c index d60eb089..682a3ddb 100644 --- a/source/pdf/pdf-xref.c +++ b/source/pdf/pdf-xref.c @@ -933,6 +933,8 @@ pdf_read_old_xref(fz_context *ctx, pdf_document *doc, pdf_lexbuf *buf) if (tok != PDF_TOK_OPEN_DICT) fz_throw(ctx, FZ_ERROR_GENERIC, "expected trailer dictionary"); + doc->has_old_style_xrefs = 1; + return pdf_parse_dict(ctx, doc, file, buf); } |