2 files changed, 11 insertions, 0 deletions
diff --git a/core/fxcrt/cfx_memorystream.cpp b/core/fxcrt/cfx_memorystream.cpp
index 345b381226..dcd21f073f 100644
--- a/core/fxcrt/cfx_memorystream.cpp
+++ b/core/fxcrt/cfx_memorystream.cpp
@@ -148,6 +148,14 @@ bool CFX_MemoryStream::WriteBlock(const void* buffer,
   return true;
 }
 
+bool CFX_MemoryStream::Seek(size_t pos) {
+  if (pos > m_nCurSize)
+    return false;
+
+  m_nCurPos = pos;
+  return true;
+}
+
 void CFX_MemoryStream::EstimateSize(size_t nInitSize, size_t nGrowSize) {
   if (m_dwFlags & Type::kConsecutive) {
     if (m_Blocks.empty()) {
diff --git a/core/fxcrt/cfx_memorystream.h b/core/fxcrt/cfx_memorystream.h
index ef66080420..a56a2dbe2c 100644
--- a/core/fxcrt/cfx_memorystream.h
+++ b/core/fxcrt/cfx_memorystream.h
@@ -28,6 +28,9 @@ class CFX_MemoryStream : public IFX_SeekableStream {
   bool WriteBlock(const void* buffer, FX_FILESIZE offset, size_t size) override;
   bool Flush() override;
 
+  // Sets the cursor position to |pos| if possible
+  bool Seek(size_t pos);
+
   bool IsConsecutive() const { return !!(m_dwFlags & Type::kConsecutive); }
 
   uint8_t* GetBuffer() const {