Add pdf_keep_document.

We have pdf_drop_document, so a pdf_keep_document seems justified
too.

2 files changed, 13 insertions, 0 deletions

diff --git a/include/mupdf/pdf/document.h b/include/mupdf/pdf/document.h
index 177f947c..68303f05 100644
--- a/include/mupdf/pdf/document.h
+++ b/include/mupdf/pdf/document.h
@@ -96,6 +96,13 @@ pdf_document *pdf_open_document_with_stream(fz_context *ctx, fz_stream *file);
 void pdf_drop_document(fz_context *ctx, pdf_document *doc);
 
 /*
+	pdf_keep_document: Keep a reference to an open document.
+
+	Does not throw exceptions.
+*/
+pdf_document *pdf_keep_document(fz_context *ctx, pdf_document *doc);
+
+/*
 	pdf_specifics: down-cast a fz_document to a pdf_document.
 	Returns NULL if underlying document is not PDF
 */
diff --git a/source/pdf/pdf-xref.c b/source/pdf/pdf-xref.c
index ba2689b9..9c98296f 100644
--- a/source/pdf/pdf-xref.c
+++ b/source/pdf/pdf-xref.c
@@ -1550,6 +1550,12 @@ pdf_drop_document(fz_context *ctx, pdf_document *doc)
 	fz_drop_document(ctx, &doc->super);
 }
 
+pdf_document *
+pdf_keep_document(fz_context *ctx, pdf_document *doc)
+{
+	return (pdf_document *)fz_keep_document(ctx, &doc->super);
+}
+
 /*
  * compressed object streams
  */