2 files changed, 11 insertions, 0 deletions
diff --git a/core/fpdfapi/parser/cpdf_read_validator.cpp b/core/fpdfapi/parser/cpdf_read_validator.cpp
index 2363f851ec..d850561bd3 100644
--- a/core/fpdfapi/parser/cpdf_read_validator.cpp
+++ b/core/fpdfapi/parser/cpdf_read_validator.cpp
@@ -125,6 +125,9 @@ bool CPDF_ReadValidator::IsWholeFileAvailable() {
 bool CPDF_ReadValidator::CheckDataRangeAndRequestIfUnavailable(
     FX_FILESIZE offset,
     size_t size) {
+  if (offset > file_size_)
+    return true;
+
   FX_SAFE_FILESIZE end_segment_offset = offset;
   end_segment_offset += size;
   // Increase checked range to allow CPDF_SyntaxParser read whole buffer.
diff --git a/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp b/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp
index 89b7e6b4de..247abaa9f4 100644
--- a/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp
+++ b/core/fpdfapi/parser/cpdf_read_validator_unittest.cpp
@@ -289,5 +289,13 @@ TEST(CPDF_ReadValidatorTest, CheckDataRangeAndRequestIfUnavailable) {
   EXPECT_FALSE(validator->read_error());
   EXPECT_TRUE(validator->has_unavailable_data());
 
+  validator->ResetErrors();
+  // Offset > file size should yield |true| and not cause a fetch.
+  EXPECT_TRUE(
+      validator->CheckDataRangeAndRequestIfUnavailable(kTestDataSize + 1, 1));
+  // No new request on already available data.
+  EXPECT_FALSE(validator->read_error());
+  EXPECT_FALSE(validator->has_unavailable_data());
+
   validator->SetDownloadHints(nullptr);
 }