Fix JPX image rendering that regressed due to several security fixes.

core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp

Index: core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
diff --git a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
index a805ffa463ed52cd64da9ffce5b23c3c602e1fcd..87b985595de2b4deb480b3ae72583ae81771c596 100644
--- a/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
+++ b/core/src/fpdfapi/fpdf_render/fpdf_render_loadimage.cpp
@@ -119,6 +119,7 @@ CPDF_DIBSource::CPDF_DIBSource()
     m_pColorSpace = NULL;
     m_bDefaultDecode = TRUE;
     m_bImageMask = FALSE;
+    m_bDoBpcCheck = TRUE;
     m_pPalette = NULL;
     m_pCompData = NULL;
     m_bColorKey = FALSE;
@@ -197,7 +198,7 @@ FX_BOOL CPDF_DIBSource::Load(CPDF_Document* pDoc, const CPDF_Stream* pStream, CP
     if (!LoadColorInfo(m_pStream->GetObjNum() != 0 ? NULL : pFormResources, pPageResources)) {
         return FALSE;
     }
-    if (m_bpc == 0 || m_nComponents == 0) {
+    if (m_bDoBpcCheck && (m_bpc == 0 || m_nComponents == 0)) {
         return FALSE;
     }
     FX_SAFE_DWORD src_pitch =
@@ -211,7 +212,8 @@ FX_BOOL CPDF_DIBSource::Load(CPDF_Document* pDoc, const CPDF_Stream* pStream, CP
         return FALSE;
     }
     const CFX_ByteString& decoder = m_pStreamAcc->GetImageDecoder();
-    if (!decoder.IsEmpty() && decoder == FX_BSTRC("CCITTFaxDecode")) {
+    if (decoder == FX_BSTRC("CCITTFaxDecode")) {
+        m_bDoBpcCheck = TRUE;
         m_bpc = 1;
     }
     if (!CreateDecoder()) {
@@ -316,7 +318,7 @@ int	CPDF_DIBSource::StartLoadDIBSource(CPDF_Document* pDoc, const CPDF_Stream* p
     if (!LoadColorInfo(m_pStream->GetObjNum() != 0 ? NULL : pFormResources, pPageResources)) {
         return 0;
     }
-    if (m_bpc == 0 || m_nComponents == 0) {
+    if (m_bDoBpcCheck && (m_bpc == 0 || m_nComponents == 0)) {
         return 0;
     }
     FX_SAFE_DWORD src_pitch =
@@ -329,6 +331,11 @@ int	CPDF_DIBSource::StartLoadDIBSource(CPDF_Document* pDoc, const CPDF_Stream* p
     if (m_pStreamAcc->GetSize() == 0 || m_pStreamAcc->GetData() == NULL) {
         return 0;
     }
+    const CFX_ByteString& decoder = m_pStreamAcc->GetImageDecoder();

[jun_fang, 2015/02/11 16:55:24]

ValidateDictParam() is used to correct parameters in dictionary. I think that we
can move this part into ValidateDictParam().

[Lei Zhang, 2015/02/13 02:15:37]

No we can't. CreateDecoder will fail first because |m_bpc| is 0, and we'll
return on line 342, so we'll never get to ValidateDictParam(). Notice how
CPDF_DIBSource::Load() above which is very similar to this function already
makes an exception for CCITTFaxDecode on line 215.

+    if (decoder == FX_BSTRC("CCITTFaxDecode")) {
+        m_bDoBpcCheck = TRUE;
+        m_bpc = 1;
+    }
     int ret = CreateDecoder();
     if (ret != 1) {
         if (!ret) {
@@ -445,12 +452,16 @@ FX_BOOL CPDF_DIBSource::LoadColorInfo(CPDF_Dictionary* pFormResources, CPDF_Dict
                 CFX_ByteString filter;
                 if (pFilter->GetType() == PDFOBJ_NAME) {
                     filter = pFilter->GetString();
-                    if (filter == FX_BSTRC("JPXDecode")) {
+                    if (filter == FX_BSTRC("JPXDecode") ||
+                        filter == FX_BSTRC("CCITTFaxDecode")) {

[jun_fang, 2015/02/11 16:55:24]

Only JPX may not have "ColorSpace". It's no need to add "CCITTFaxDecode" here.

[Lei Zhang, 2015/02/13 02:15:37]

Can you suggest some other way for CCITTFaxDecode to pass the |m_bpc| /
|m_nComponents| check right after LoadColorInfo() returns? Without this, they
will fail the check because we don't set |m_bpc| for CCITTFaxDecode until later.

[Lei Zhang, 2015/02/13 02:51:07]

Oh, nevermind. I understand what you are saying.

+                        m_bDoBpcCheck = FALSE;
                         return TRUE;
                     }
                 } else if (pFilter->GetType() == PDFOBJ_ARRAY) {
                     CPDF_Array* pArray = (CPDF_Array*)pFilter;
-                    if (pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("JPXDecode")) {
+                    if (pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("JPXDecode") ||
+                        pArray->GetString(pArray->GetCount() - 1) == FX_BSTRC("CCITTFaxDecode")) {

[jun_fang, 2015/02/11 16:55:24]

Only JPX may not have "ColorSpace". It's no need to add "CCITTFaxDecode" here.

+                        m_bDoBpcCheck = FALSE;
                         return TRUE;
                     }
                 }
@@ -560,7 +571,7 @@ int CPDF_DIBSource::CreateDecoder()
     if (decoder.IsEmpty()) {
         return 1;
     }
-    if (m_bpc == 0) {
+    if (m_bDoBpcCheck && m_bpc == 0) {
         return 0;
     }
     FX_LPCBYTE src_data = m_pStreamAcc->GetData();