From 668e6fb14e0235d07aff4344e01308832e2ad6a7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Robert=20M=C3=BCller?= <robytemueller@gmail.com>
Date: Wed, 11 Oct 2023 23:45:50 +0200
Subject: [PATCH] Use member variables for demo player snapshot data

Use member instead of static variables for demo player snapshot data. The static variables would otherwise cause issues when multiple demo players are playing at the same time, especially demo players used in background jobs for replay demo slicing. This hopefully closes #7068.
---
 src/engine/shared/demo.cpp | 26 +++++++++++---------------
 src/engine/shared/demo.h   |  4 ++++
 2 files changed, 15 insertions(+), 15 deletions(-)

diff --git a/src/engine/shared/demo.cpp b/src/engine/shared/demo.cpp
index 57478f9a7..fc9b878db 100644
--- a/src/engine/shared/demo.cpp
+++ b/src/engine/shared/demo.cpp
@@ -587,11 +587,9 @@ void CDemoPlayer::DoTick()
 
 		// read the chunk
 		int DataSize = 0;
-		static char s_aData[CSnapshot::MAX_SIZE];
 		if(ChunkSize)
 		{
-			static char s_aCompresseddata[CSnapshot::MAX_SIZE];
-			if(io_read(m_File, s_aCompresseddata, ChunkSize) != (unsigned)ChunkSize)
+			if(io_read(m_File, m_aCompressedSnapshotData, ChunkSize) != (unsigned)ChunkSize)
 			{
 				// stop on error or eof
 				if(m_pConsole)
@@ -600,8 +598,7 @@ void CDemoPlayer::DoTick()
 				break;
 			}
 
-			static char s_aDecompressed[CSnapshot::MAX_SIZE];
-			DataSize = CNetBase::Decompress(s_aCompresseddata, ChunkSize, s_aDecompressed, sizeof(s_aDecompressed));
+			DataSize = CNetBase::Decompress(m_aCompressedSnapshotData, ChunkSize, m_aDecompressedSnapshotData, sizeof(m_aDecompressedSnapshotData));
 			if(DataSize < 0)
 			{
 				// stop on error or eof
@@ -611,7 +608,7 @@ void CDemoPlayer::DoTick()
 				break;
 			}
 
-			DataSize = CVariableInt::Decompress(s_aDecompressed, DataSize, s_aData, sizeof(s_aData));
+			DataSize = CVariableInt::Decompress(m_aDecompressedSnapshotData, DataSize, m_aCurrentSnapshotData, sizeof(m_aCurrentSnapshotData));
 
 			if(DataSize < 0)
 			{
@@ -625,9 +622,8 @@ void CDemoPlayer::DoTick()
 		if(ChunkType == CHUNKTYPE_DELTA)
 		{
 			// process delta snapshot
-			static char s_aNewsnap[CSnapshot::MAX_SIZE];
-			CSnapshot *pNewsnap = (CSnapshot *)s_aNewsnap;
-			DataSize = m_pSnapshotDelta->UnpackDelta((CSnapshot *)m_aLastSnapshotData, pNewsnap, s_aData, DataSize);
+			CSnapshot *pNewsnap = (CSnapshot *)m_aDeltaSnapshotData;
+			DataSize = m_pSnapshotDelta->UnpackDelta((CSnapshot *)m_aLastSnapshotData, pNewsnap, m_aCurrentSnapshotData, DataSize);
 
 			if(DataSize < 0)
 			{
@@ -650,17 +646,17 @@ void CDemoPlayer::DoTick()
 			else
 			{
 				if(m_pListener)
-					m_pListener->OnDemoPlayerSnapshot(s_aNewsnap, DataSize);
+					m_pListener->OnDemoPlayerSnapshot(m_aDeltaSnapshotData, DataSize);
 
 				m_LastSnapshotDataSize = DataSize;
-				mem_copy(m_aLastSnapshotData, s_aNewsnap, DataSize);
+				mem_copy(m_aLastSnapshotData, m_aDeltaSnapshotData, DataSize);
 				GotSnapshot = true;
 			}
 		}
 		else if(ChunkType == CHUNKTYPE_SNAPSHOT)
 		{
 			// process full snapshot
-			CSnapshot *pSnap = (CSnapshot *)s_aData;
+			CSnapshot *pSnap = (CSnapshot *)m_aCurrentSnapshotData;
 			if(!pSnap->IsValid(DataSize))
 			{
 				if(m_pConsole)
@@ -675,9 +671,9 @@ void CDemoPlayer::DoTick()
 				GotSnapshot = true;
 
 				m_LastSnapshotDataSize = DataSize;
-				mem_copy(m_aLastSnapshotData, s_aData, DataSize);
+				mem_copy(m_aLastSnapshotData, m_aCurrentSnapshotData, DataSize);
 				if(m_pListener)
-					m_pListener->OnDemoPlayerSnapshot(s_aData, DataSize);
+					m_pListener->OnDemoPlayerSnapshot(m_aCurrentSnapshotData, DataSize);
 			}
 		}
 		else
@@ -698,7 +694,7 @@ void CDemoPlayer::DoTick()
 			else if(ChunkType == CHUNKTYPE_MESSAGE)
 			{
 				if(m_pListener)
-					m_pListener->OnDemoPlayerMessage(s_aData, DataSize);
+					m_pListener->OnDemoPlayerMessage(m_aCurrentSnapshotData, DataSize);
 			}
 		}
 	}
diff --git a/src/engine/shared/demo.h b/src/engine/shared/demo.h
index 5917eaeda..eeeaee59e 100644
--- a/src/engine/shared/demo.h
+++ b/src/engine/shared/demo.h
@@ -114,6 +114,10 @@ private:
 
 	CPlaybackInfo m_Info;
 	int m_DemoType;
+	unsigned char m_aCompressedSnapshotData[CSnapshot::MAX_SIZE];
+	unsigned char m_aDecompressedSnapshotData[CSnapshot::MAX_SIZE];
+	unsigned char m_aCurrentSnapshotData[CSnapshot::MAX_SIZE];
+	unsigned char m_aDeltaSnapshotData[CSnapshot::MAX_SIZE];
 	unsigned char m_aLastSnapshotData[CSnapshot::MAX_SIZE];
 	int m_LastSnapshotDataSize;
 	class CSnapshotDelta *m_pSnapshotDelta;