CPWL_Color::ConvertColorType should compare current color type with the given convert color type.

fpdfsdk/pdfwindow/PWL_Utils.cpp

Index: fpdfsdk/pdfwindow/PWL_Utils.cpp
diff --git a/fpdfsdk/pdfwindow/PWL_Utils.cpp b/fpdfsdk/pdfwindow/PWL_Utils.cpp
index 823873f19dfeca9a314d2ad9e91e853746c086c8..0574454c4f95577ebfb42bdb20911e0c26350e0a 100644
--- a/fpdfsdk/pdfwindow/PWL_Utils.cpp
+++ b/fpdfsdk/pdfwindow/PWL_Utils.cpp
@@ -3308,12 +3308,15 @@ void CPWL_Utils::GetGraphics_Foxit(CFX_ByteString& sPathData,
     GetPathDataFromArray(path, PathArray, 23);
 }
 
-void CPWL_Color::ConvertColorType(int32_t other_nColorType) {
-  switch (other_nColorType) {
+void CPWL_Color::ConvertColorType(int32_t nConvertColorType) {
+  if (nColorType == nConvertColorType)
+    return;
+
+  switch (nColorType) {

[dsinclair, 2016/09/09 00:09:26]

Are we sure nColorType is the correct item for the outer switch? It's hard to
tell from reading the code if the colour we're going too should be here, or the
colour we're going from.

[jaepark, 2016/09/09 00:39:41]

Since the inner switch is calling functions OUTER2INNER, I think the color we're
going from is in the outer switch.

     case COLORTYPE_TRANSPARENT:
       break;
     case COLORTYPE_GRAY:
-      switch (other_nColorType) {
+      switch (nConvertColorType) {
         case COLORTYPE_RGB:
           CPWL_Utils::ConvertGRAY2RGB(fColor1, fColor1, fColor2, fColor3);
           break;
@@ -3324,7 +3327,7 @@ void CPWL_Color::ConvertColorType(int32_t other_nColorType) {
       }
       break;
     case COLORTYPE_RGB:
-      switch (other_nColorType) {
+      switch (nConvertColorType) {
         case COLORTYPE_GRAY:
           CPWL_Utils::ConvertRGB2GRAY(fColor1, fColor2, fColor3, fColor1);
           break;
@@ -3335,7 +3338,7 @@ void CPWL_Color::ConvertColorType(int32_t other_nColorType) {
       }
       break;
     case COLORTYPE_CMYK:
-      switch (other_nColorType) {
+      switch (nConvertColorType) {
         case COLORTYPE_GRAY:
           CPWL_Utils::ConvertCMYK2GRAY(fColor1, fColor2, fColor3, fColor4,
                                        fColor1);
@@ -3347,5 +3350,5 @@ void CPWL_Color::ConvertColorType(int32_t other_nColorType) {
       }
       break;
   }
-  nColorType = other_nColorType;
+  nColorType = nConvertColorType;
 }