1 files changed, 18 insertions, 3 deletions

diff --git a/core/fpdfdoc/cpdf_annotlist.cpp b/core/fpdfdoc/cpdf_annotlist.cpp
index 1f94779c15..e4ecf466f5 100644
--- a/core/fpdfdoc/cpdf_annotlist.cpp
+++ b/core/fpdfdoc/cpdf_annotlist.cpp
@@ -6,6 +6,7 @@
 
 #include "core/fpdfdoc/cpdf_annotlist.h"
 
+#include <algorithm>
 #include <memory>
 #include <utility>
 
@@ -26,7 +27,8 @@
 namespace {
 
 std::unique_ptr<CPDF_Annot> CreatePopupAnnot(CPDF_Annot* pAnnot,
-                                             CPDF_Document* pDocument) {
+                                             CPDF_Document* pDocument,
+                                             CPDF_Page* pPage) {
   CPDF_Dictionary* pParentDict = pAnnot->GetAnnotDict();
   if (!pParentDict)
     return nullptr;
@@ -48,7 +50,20 @@ std::unique_ptr<CPDF_Annot> CreatePopupAnnot(CPDF_Annot* pAnnot,
   CFX_FloatRect rect = pParentDict->GetRectFor("Rect");
   rect.Normalize();
   CFX_FloatRect popupRect(0, 0, 200, 200);
-  popupRect.Translate(rect.left, rect.bottom - popupRect.Height());
+  // Note that if the popup can set its own dimensions, then we will need to
+  // make sure that it isn't larger than the page size.
+  if (rect.left + popupRect.Width() > pPage->GetPageWidth() &&
+      rect.bottom - popupRect.Height() < 0) {
+    // If the annotation is on the bottom-right corner of the page, then place
+    // the popup above and to the left of the annotation.
+    popupRect.Translate(rect.right - popupRect.Width(), rect.top);
+  } else {
+    // Place the popup below and to the right of the annotation without getting
+    // clipped by page edges.
+    popupRect.Translate(
+        std::min(rect.left, pPage->GetPageWidth() - popupRect.Width()),
+        std::max(rect.bottom - popupRect.Height(), 0.f));
+  }
 
   pAnnotDict->SetRectFor("Rect", popupRect);
   pAnnotDict->SetNewFor<CPDF_Number>("F", 0);
@@ -94,7 +109,7 @@ CPDF_AnnotList::CPDF_AnnotList(CPDF_Page* pPage)
   size_t nAnnotListSize = m_AnnotList.size();
   for (size_t i = 0; i < nAnnotListSize; ++i) {
     std::unique_ptr<CPDF_Annot> pPopupAnnot(
-        CreatePopupAnnot(m_AnnotList[i].get(), m_pDocument));
+        CreatePopupAnnot(m_AnnotList[i].get(), m_pDocument, pPage));
     if (pPopupAnnot)
       m_AnnotList.push_back(std::move(pPopupAnnot));
   }