From 2bbcd9997673ee6b384478d4f45de10c686aea04 Mon Sep 17 00:00:00 2001
From: Tonya Souther <tonya.souther@gmail.com>
Date: Tue, 11 Jan 2011 10:50:27 -0600
Subject: [PATCH] Handle PNG images with background color specified correctly
 (ignore the background). From ThickBrick Sleaford, fixes VWR-24420/STORM-839.

---
 indra/llimage/llpngwrapper.cpp | 21 +++++----------------
 indra/llimage/llpngwrapper.h   |  3 ---
 2 files changed, 5 insertions(+), 19 deletions(-)

diff --git a/indra/llimage/llpngwrapper.cpp b/indra/llimage/llpngwrapper.cpp
index fe737e2072..5e32b40e08 100644
--- a/indra/llimage/llpngwrapper.cpp
+++ b/indra/llimage/llpngwrapper.cpp
@@ -50,8 +50,6 @@ LLPngWrapper::LLPngWrapper()
 	  mCompressionType( 0 ),
 	  mFilterMethod( 0 ),
 	  mFinalSize( 0 ),
-	  mHasBKGD(false),
-	  mBackgroundColor(),
 	  mGamma(0.f)
 {
 }
@@ -111,11 +109,10 @@ void LLPngWrapper::writeFlush(png_structp png_ptr)
 }
 
 // Read the PNG file using the libpng.  The low-level interface is used here
-// because we want to do various transformations (including setting the
-// matte background if any, and applying gama) which can't be done with
-// the high-level interface. The scanline also begins at the bottom of
-// the image (per SecondLife conventions) instead of at the top, so we
-// must assign row-pointers in "reverse" order.
+// because we want to do various transformations (including applying gamma)
+// which can't be done with the high-level interface.  The scanline also
+// begins at the bottom of the image (per SecondLife conventions) instead of
+// at the top, so we must assign row-pointers in "reverse" order.
 BOOL LLPngWrapper::readPng(U8* src, LLImageRaw* rawImage, ImageInfo *infop)
 {
 	try
@@ -201,8 +198,7 @@ void LLPngWrapper::normalizeImage()
 	//		2. Convert grayscales to RGB
 	//		3. Create alpha layer from transparency
 	//		4. Ensure 8-bpp for all images
-	//		5. Apply background matte if any
-	//		6. Set (or guess) gamma
+	//		5. Set (or guess) gamma
 
 	if (mColorType == PNG_COLOR_TYPE_PALETTE)
 	{
@@ -229,12 +225,6 @@ void LLPngWrapper::normalizeImage()
 	{
 		png_set_strip_16(mReadPngPtr);
 	}
-	mHasBKGD = png_get_bKGD(mReadPngPtr, mReadInfoPtr, &mBackgroundColor);
-	if (mHasBKGD)
-	{
-		png_set_background(mReadPngPtr, mBackgroundColor,
-			PNG_BACKGROUND_GAMMA_FILE, 1, 1.0);
-	}
 
 #if LL_DARWIN
 	const F64 SCREEN_GAMMA = 1.8;
@@ -261,7 +251,6 @@ void LLPngWrapper::updateMetaData()
     mBitDepth = png_get_bit_depth(mReadPngPtr, mReadInfoPtr);
     mColorType = png_get_color_type(mReadPngPtr, mReadInfoPtr);
 	mChannels = png_get_channels(mReadPngPtr, mReadInfoPtr);
-	mHasBKGD = png_get_bKGD(mReadPngPtr, mReadInfoPtr, &mBackgroundColor);
 }
 
 // Method to write raw image into PNG at dest. The raw scanline begins
diff --git a/indra/llimage/llpngwrapper.h b/indra/llimage/llpngwrapper.h
index 47a4207d66..739f435996 100644
--- a/indra/llimage/llpngwrapper.h
+++ b/indra/llimage/llpngwrapper.h
@@ -88,9 +88,6 @@ private:
 
 	U32 mFinalSize;
 
-	bool mHasBKGD;
-	png_color_16p mBackgroundColor;
-
 	F64 mGamma;
 
 	std::string mErrorMessage;