3 files changed, 10 insertions, 3 deletions
diff --git a/indra/llappearance/lltexlayer.cpp b/indra/llappearance/lltexlayer.cpp
index 3430a25536..e1a3a83841 100644
--- a/indra/llappearance/lltexlayer.cpp
+++ b/indra/llappearance/lltexlayer.cpp
@@ -1509,7 +1509,14 @@ void LLTexLayer::renderMorphMasks(S32 x, S32 y, S32 width, S32 height, const LLC
                 }
                 else
                 { // platforms with working drivers...
-				    glReadPixels(x, y, width, height, GL_ALPHA, GL_UNSIGNED_BYTE, alpha_data);                
+                    // We just want GL_ALPHA, but that isn't supported in OGL core profile 4.
+                    static const size_t TEMP_BYTES_PER_PIXEL = 4;
+                    U8* temp_data = (U8*)ll_aligned_malloc_32(mem_size * TEMP_BYTES_PER_PIXEL);
+                    glReadPixels(x, y, width, height, GL_RGBA, GL_UNSIGNED_BYTE, temp_data);
+                    for (size_t pixel = 0; pixel < pixels; pixel++) {
+                        alpha_data[pixel] = temp_data[(pixel * TEMP_BYTES_PER_PIXEL) + 3];
+                    }
+                    ll_aligned_free_32(temp_data);
                 }
 			}
             else
diff --git a/indra/llappearance/lltexlayerparams.cpp b/indra/llappearance/lltexlayerparams.cpp
index ce5c7142d5..06b4f6c75a 100644
--- a/indra/llappearance/lltexlayerparams.cpp
+++ b/indra/llappearance/lltexlayerparams.cpp
@@ -151,7 +151,7 @@ LLTexLayerParamAlpha::LLTexLayerParamAlpha(const LLTexLayerParamAlpha& pOther)
 	mCachedProcessedTexture(pOther.mCachedProcessedTexture),
 	mStaticImageTGA(pOther.mStaticImageTGA),
 	mStaticImageRaw(pOther.mStaticImageRaw),
-	mNeedsCreateTexture(pOther.mNeedsCreateTexture),
+	mNeedsCreateTexture(pOther.mNeedsCreateTexture.load()),
 	mStaticImageInvalid(pOther.mStaticImageInvalid),
 	mAvgDistortionVec(pOther.mAvgDistortionVec),
 	mCachedEffectiveWeight(pOther.mCachedEffectiveWeight)
diff --git a/indra/llappearance/lltexlayerparams.h b/indra/llappearance/lltexlayerparams.h
index e2440998b3..000f55685e 100644
--- a/indra/llappearance/lltexlayerparams.h
+++ b/indra/llappearance/lltexlayerparams.h
@@ -100,7 +100,7 @@ private:
 	LLPointer<LLGLTexture>	mCachedProcessedTexture;
 	LLPointer<LLImageTGA>	mStaticImageTGA;
 	LLPointer<LLImageRaw>	mStaticImageRaw;
-	BOOL					mNeedsCreateTexture;
+	std::atomic<BOOL>		mNeedsCreateTexture;
 	BOOL					mStaticImageInvalid;
 	LL_ALIGN_16(LLVector4a				mAvgDistortionVec);
 	F32						mCachedEffectiveWeight;