Adjust the order of clearing resource in CPDF_DocPageData::Clear

core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp

Index: core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
diff --git a/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp b/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
index 77db4534fbd27f345ede1a73f9cb5ce3bbaea08e..eb6482dbb282b1ac3a774db3b65a652a04e090fa 100644
--- a/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
+++ b/core/src/fpdfapi/fpdf_page/fpdf_page_doc.cpp
@@ -165,18 +165,6 @@ void CPDF_DocPageData::Clear(FX_BOOL bForceRelease)
             fontData->m_Obj = NULL;
         }
     }
-    pos = m_ImageMap.GetStartPosition();
-    while (pos) {
-        FX_DWORD objNum;
-        CPDF_CountedObject<CPDF_Image*>* imageData;
-        m_ImageMap.GetNextAssoc(pos, objNum, imageData);
-        nCount = imageData->m_nCount;
-        if (bForceRelease || nCount < 2) {
-            delete imageData->m_Obj;
-            delete imageData;
-            m_ImageMap.RemoveKey(objNum);
-        }
-    }
     pos = m_ColorSpaceMap.GetStartPosition();
     while (pos) {
         CPDF_Object* csKey;
@@ -229,9 +217,23 @@ void CPDF_DocPageData::Clear(FX_BOOL bForceRelease)
         m_PatternMap.GetNextAssoc(pos, ptObj, ptData);
         nCount = ptData->m_nCount;

[Tom Sepez, 2014/09/19 17:36:31]

nit: if ptObj->m_obj is NULL, we can short-circuit execution here with a
"continue" before even considering m_nCount. And you may not need the local
m_nCount since its only used once (in the if below) and ptData->m_nCount is just
fine to use there. I think the loop reads clearer that way.

         if (bForceRelease || nCount < 2) {
-            ptData->m_Obj->SetForceClear(bForceRelease);
-            delete ptData->m_Obj;
-            ptData->m_Obj = NULL;
+            if (ptData->m_Obj) {
+                ptData->m_Obj->SetForceClear(bForceRelease);
+                delete ptData->m_Obj;
+                ptData->m_Obj = NULL;
+            }
+        }
+    }
+    pos = m_ImageMap.GetStartPosition();
+    while (pos) {
+        FX_DWORD objNum;
+        CPDF_CountedObject<CPDF_Image*>* imageData;
+        m_ImageMap.GetNextAssoc(pos, objNum, imageData);
+        nCount = imageData->m_nCount;
+        if (bForceRelease || nCount < 2) {
+            delete imageData->m_Obj;

[Tom Sepez, 2014/09/19 17:36:31]

do we need to check imageData->m_obj for NULLness here too?

+            delete imageData;
+            m_ImageMap.RemoveKey(objNum);
         }
     }
 }