summaryrefslogtreecommitdiff
path: root/core/fpdfapi/parser
diff options
context:
space:
mode:
Diffstat (limited to 'core/fpdfapi/parser')
-rw-r--r--core/fpdfapi/parser/cpdf_cross_ref_table.cpp35
-rw-r--r--core/fpdfapi/parser/cpdf_cross_ref_table.h7
-rw-r--r--core/fpdfapi/parser/cpdf_parser.cpp12
-rw-r--r--core/fpdfapi/parser/cpdf_parser.h2
4 files changed, 40 insertions, 16 deletions
diff --git a/core/fpdfapi/parser/cpdf_cross_ref_table.cpp b/core/fpdfapi/parser/cpdf_cross_ref_table.cpp
index 77c0e8136c..d25c5e0167 100644
--- a/core/fpdfapi/parser/cpdf_cross_ref_table.cpp
+++ b/core/fpdfapi/parser/cpdf_cross_ref_table.cpp
@@ -4,11 +4,21 @@
#include "core/fpdfapi/parser/cpdf_cross_ref_table.h"
+#include <algorithm>
#include <utility>
#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_number.h"
#include "core/fpdfapi/parser/cpdf_parser.h"
+namespace {
+
+constexpr char kXRefStm[] = "XRefStm";
+constexpr char kPrev[] = "Prev";
+constexpr char kSize[] = "Size";
+
+} // namespace
+
// static
std::unique_ptr<CPDF_CrossRefTable> CPDF_CrossRefTable::MergeUp(
std::unique_ptr<CPDF_CrossRefTable> current,
@@ -102,16 +112,24 @@ void CPDF_CrossRefTable::Update(
UpdateTrailer(std::move(new_cross_ref->trailer_));
}
-void CPDF_CrossRefTable::ShrinkObjectMap(uint32_t objnum) {
- if (objnum == 0) {
+void CPDF_CrossRefTable::ShrinkObjectMap(uint32_t max_size) {
+ if (max_size == 0) {
objects_info_.clear();
return;
}
- objects_info_.erase(objects_info_.lower_bound(objnum), objects_info_.end());
+ objects_info_.erase(objects_info_.lower_bound(max_size), objects_info_.end());
+}
+
+uint32_t CPDF_CrossRefTable::GetSize() const {
+ const uint32_t size_from_objects_num =
+ objects_info_.empty() ? 0 : (objects_info_.rbegin()->first + 1);
+ const int size_from_trailer = trailer() ? trailer()->GetIntegerFor(kSize) : 0;
+ if (size_from_trailer <= 0)
+ return size_from_objects_num;
- if (!pdfium::ContainsKey(objects_info_, objnum - 1))
- objects_info_[objnum - 1].pos = 0;
+ return std::max(static_cast<uint32_t>(size_from_trailer),
+ size_from_objects_num);
}
void CPDF_CrossRefTable::UpdateInfo(
@@ -149,8 +167,11 @@ void CPDF_CrossRefTable::UpdateTrailer(
return;
}
- new_trailer->SetFor("XRefStm", trailer_->RemoveFor("XRefStm"));
- new_trailer->SetFor("Prev", trailer_->RemoveFor("Prev"));
+ new_trailer->RemoveFor(kXRefStm);
+ new_trailer->RemoveFor(kPrev);
+ new_trailer->SetNewFor<CPDF_Number>(
+ kSize, std::max(trailer_->GetIntegerFor(kSize),
+ new_trailer->GetIntegerFor(kSize)));
for (auto it = new_trailer->begin(); it != new_trailer->end();) {
const ByteString key = it->first;
diff --git a/core/fpdfapi/parser/cpdf_cross_ref_table.h b/core/fpdfapi/parser/cpdf_cross_ref_table.h
index 9631216b0c..d8bda7125f 100644
--- a/core/fpdfapi/parser/cpdf_cross_ref_table.h
+++ b/core/fpdfapi/parser/cpdf_cross_ref_table.h
@@ -60,7 +60,12 @@ class CPDF_CrossRefTable {
void Update(std::unique_ptr<CPDF_CrossRefTable> new_cross_ref);
- void ShrinkObjectMap(uint32_t objnum);
+ void ShrinkObjectMap(uint32_t max_size);
+
+ // The total number of entries in the file’s cross-reference table, as
+ // defined by the combination of the original section and all update
+ // section.
+ uint32_t GetSize() const;
private:
void UpdateInfo(std::map<uint32_t, ObjectInfo>&& new_objects_info);
diff --git a/core/fpdfapi/parser/cpdf_parser.cpp b/core/fpdfapi/parser/cpdf_parser.cpp
index e93f293f84..cb262bd1eb 100644
--- a/core/fpdfapi/parser/cpdf_parser.cpp
+++ b/core/fpdfapi/parser/cpdf_parser.cpp
@@ -72,9 +72,8 @@ CPDF_Parser::~CPDF_Parser() {
}
uint32_t CPDF_Parser::GetLastObjNum() const {
- return m_CrossRefTable->objects_info().empty()
- ? 0
- : m_CrossRefTable->objects_info().rbegin()->first;
+ const uint32_t size = m_CrossRefTable->GetSize();
+ return size ? size - 1 : 0;
}
bool CPDF_Parser::IsValidObjectNumber(uint32_t objnum) const {
@@ -115,8 +114,8 @@ bool CPDF_Parser::IsObjectFree(uint32_t objnum) const {
return GetObjectType(objnum) == ObjectType::kFree;
}
-void CPDF_Parser::ShrinkObjectMap(uint32_t objnum) {
- m_CrossRefTable->ShrinkObjectMap(objnum);
+void CPDF_Parser::ShrinkObjectMap(uint32_t max_size) {
+ m_CrossRefTable->ShrinkObjectMap(max_size);
}
bool CPDF_Parser::InitSyntaxParser(
@@ -746,8 +745,7 @@ bool CPDF_Parser::LoadCrossRefV5(FX_FILESIZE* pos, bool bMainXRef) {
const uint8_t* segstart = pData + segindex * totalWidth;
FX_SAFE_UINT32 dwMaxObjNum = startnum;
dwMaxObjNum += count;
- uint32_t dwV5Size =
- m_CrossRefTable->objects_info().empty() ? 0 : GetLastObjNum() + 1;
+ uint32_t dwV5Size = m_CrossRefTable->GetSize();
if (!dwMaxObjNum.IsValid() || dwMaxObjNum.ValueOrDie() > dwV5Size)
continue;
diff --git a/core/fpdfapi/parser/cpdf_parser.h b/core/fpdfapi/parser/cpdf_parser.h
index c07c932cf4..81d23e65b9 100644
--- a/core/fpdfapi/parser/cpdf_parser.h
+++ b/core/fpdfapi/parser/cpdf_parser.h
@@ -145,7 +145,7 @@ class CPDF_Parser {
Error LoadLinearizedMainXRefTable();
const CPDF_ObjectStream* GetObjectStream(uint32_t object_number);
std::unique_ptr<CPDF_LinearizedHeader> ParseLinearizedHeader();
- void ShrinkObjectMap(uint32_t size);
+ void ShrinkObjectMap(uint32_t max_size);
// A simple check whether the cross reference table matches with
// the objects.
bool VerifyCrossRefV4();