in the attempt to fix 627393, changed IFX_FileRead's readBlock to return the length it reads

core/fpdfapi/edit/fpdf_edit_create.cpp

Index: core/fpdfapi/edit/fpdf_edit_create.cpp
diff --git a/core/fpdfapi/edit/fpdf_edit_create.cpp b/core/fpdfapi/edit/fpdf_edit_create.cpp
index a578a0a1141c81f80a64634c54c098b7ae428fed..7689ba7cb8381a0b86dfac1b4e22b0af68c318a0 100644
--- a/core/fpdfapi/edit/fpdf_edit_create.cpp
+++ b/core/fpdfapi/edit/fpdf_edit_create.cpp
@@ -1494,7 +1494,9 @@ int32_t CPDF_Creator::WriteDoc_Stage1(IFX_Pause* pPause) {
       uint32_t src_size = (uint32_t)(uintptr_t)m_Pos;
       while (src_size) {
         uint32_t block_size = src_size > 4096 ? 4096 : src_size;
-        if (!pSrcFile->ReadBlock(buffer, m_Offset - src_size, block_size)) {
+        if (pSrcFile->ReadBlock(buffer, m_Offset - src_size, block_size) !=
+                block_size &&
+            !pSrcFile->IsEOF()) {
           return -1;
         }
         if (m_File.AppendBlock(buffer, block_size) < 0) {

[Tom Sepez, 2016/11/14 20:27:40]

we could have a short read here, yet we appended the full block_size.