From b785b9d1ae08f5f05c6c4ebdb127c5debbb225c7 Mon Sep 17 00:00:00 2001
From: Beq <BeqJanus@vcs.firestormviewer.org>
Date: Thu, 22 Oct 2020 22:52:02 +0100
Subject: [PATCH] Crash avoidance for compositeUnscaled4onto3

---
 indra/llimage/llimage.cpp         | 31 +++++++++++++++++++++++++++----
 indra/newview/llvlcomposition.cpp |  8 ++++++++
 2 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/indra/llimage/llimage.cpp b/indra/llimage/llimage.cpp
index 9b33aac1c4..246f3058b1 100644
--- a/indra/llimage/llimage.cpp
+++ b/indra/llimage/llimage.cpp
@@ -1079,9 +1079,10 @@ void LLImageRaw::composite( LLImageRaw* src )
 		return;
 	}
 
-	llassert(3 == src->getComponents());
-	llassert(3 == dst->getComponents());
-
+// <FS:Beq> These assertions are nonsense.
+	// llassert(3 == src->getComponents());
+	// llassert(3 == dst->getComponents());
+// </FS:Beq>
 	if( 3 == dst->getComponents() )
 	{
 		if( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) )
@@ -1143,12 +1144,34 @@ void LLImageRaw::compositeUnscaled4onto3( LLImageRaw* src )
 {
 	LLImageRaw* dst = this;  // Just for clarity.
 
-	llassert( (3 == src->getComponents()) || (4 == src->getComponents()) );
+	// <FS:Beq> Correct bad assertion
+	// llassert( (3 == src->getComponents()) || (4 == src->getComponents()) );
+	llassert( (4 == src->getComponents()) || (3 == dst->getComponents()) );
+	// </FS:Beq>
 	llassert( (src->getWidth() == dst->getWidth()) && (src->getHeight() == dst->getHeight()) );
 
 	U8* src_data = src->getData();
 	U8* dst_data = dst->getData();
 	S32 pixels = getWidth() * getHeight();
+	// <FS:Beq> suspicious crash avoid potential causes.
+	if(!src_data)
+	{
+		LL_WARNS() << "source is null!" << LL_ENDL;
+		return;
+	}
+	if(!dst_data)
+	{
+		LL_WARNS() << "destination is null!" << LL_ENDL;
+		return;
+	}
+	auto src_comps = src->getComponents();
+	if( src_comps != 4)
+	{
+		// This should never be reached, buit apparently it is.
+		LL_WARNS() << "src has incorrect number of layers (" << src_comps << ")" << LL_ENDL;
+		return;
+	}
+	// </FS:Beq>
 	while( pixels-- )
 	{
 		U8 alpha = src_data[3];
diff --git a/indra/newview/llvlcomposition.cpp b/indra/newview/llvlcomposition.cpp
index 25326f7e05..8ba0f89fdc 100644
--- a/indra/newview/llvlcomposition.cpp
+++ b/indra/newview/llvlcomposition.cpp
@@ -307,6 +307,14 @@ BOOL LLVLComposition::generateTexture(const F32 x, const F32 y,
 				mDetailTextures[i]->getComponents() != 3)
 			{
 				LLPointer<LLImageRaw> newraw = new LLImageRaw(BASE_SIZE, BASE_SIZE, 3);
+				//<FS:Beq> guard against bad alloc here that leads to crash in composite
+				if(!newraw)
+				{
+					// Not much that is useful to do here, this ship is sinking it seems.
+					LL_WARNS("Terrain") << "allocation of new raw image failed" << LL_ENDL;
+					return(FALSE);
+				}
+				// </FS:Beq>
 				newraw->composite(mRawImages[i]);
 				mRawImages[i] = newraw; // deletes old
 			}