Reset state in QPDF::calculateLinearizationData

This makes it possible to use two different writers to write
linearized files from the same QPDF object.

2 files changed, 15 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index ec165929..ad86b396 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2012-09-06  Jay Berkenbilt  <ejb@ql.org>
 
+	* Make it possible to write the same QPDF object with two
+	different QPDFWriter objects that have both called
+	setLinearization(true) by making private method
+	QPDF::calculateLinearizationData() properly initialize its state.
+
 	* Bug fix: Writing after calling QPDFWriter::setOutputMemory()
 	would cause a segmentation fault because of an internal field not
 	being initialized, rendering that method useless.  This has been
diff --git a/libqpdf/QPDF_linearization.cc b/libqpdf/QPDF_linearization.cc
index fdd0d702..65f2b99e 100644
--- a/libqpdf/QPDF_linearization.cc
+++ b/libqpdf/QPDF_linearization.cc
@@ -1241,6 +1241,16 @@ QPDF::calculateLinearizationData(std::map<int, int> const& object_stream_data)
 
     //   * outlines: part 6 or 9
 
+    this->part4.clear();
+    this->part6.clear();
+    this->part7.clear();
+    this->part8.clear();
+    this->part9.clear();
+    this->c_linp = LinParameters();
+    this->c_page_offset_data = CHPageOffset();
+    this->c_shared_object_data = CHSharedObject();
+    this->c_outline_data = HGeneric();
+
     QPDFObjectHandle root = getRoot();
     bool outlines_in_first_page = false;
     QPDFObjectHandle pagemode = root.getKey("/PageMode");