Merge pull request #8243 from Robyt3/Console-Scrolling-Fix

Fix potential client crash and console not keeping scrolling position when console backlog is full

src/engine/shared/ringbuffer.cpp

@@ -123,11 +123,21 @@ void *CRingBufferBase::Allocate(int Size)
 	return (void *)(pBlock + 1);
 }
 
+void CRingBufferBase::SetPopCallback(std::function<void(void *pCurrent)> PopCallback)
+{
+	m_PopCallback = std::move(PopCallback);
+}
+
 int CRingBufferBase::PopFirst()
 {
 	if(m_pConsume->m_Free)
 		return 0;
 
+	if(m_PopCallback)
+	{
+		m_PopCallback(m_pConsume + 1);
+	}
+
 	// set the free flag
 	m_pConsume->m_Free = 1;
 

src/engine/shared/ringbuffer.h

@@ -5,6 +5,8 @@
 
 #include <base/system.h>
 
+#include <functional>
+
 class CRingBufferBase
 {
 	class CItem
@@ -25,6 +27,8 @@ class CRingBufferBase
 	int m_Size;
 	int m_Flags;
 
+	std::function<void(void *pCurrent)> m_PopCallback = nullptr;
+
 	CItem *NextBlock(CItem *pItem);
 	CItem *PrevBlock(CItem *pItem);
 	CItem *MergeBack(CItem *pItem);
@@ -39,6 +43,7 @@ protected:
 
 	void Init(void *pMemory, int Size, int Flags);
 	int PopFirst();
+	void SetPopCallback(const std::function<void(void *pCurrent)> PopCallback);
 
 public:
 	enum
@@ -55,6 +60,12 @@ class CTypedRingBuffer : public CRingBufferBase
 public:
 	T *Allocate(int Size) { return (T *)CRingBufferBase::Allocate(Size); }
 	int PopFirst() { return CRingBufferBase::PopFirst(); }
+	void SetPopCallback(std::function<void(T *pCurrent)> PopCallback)
+	{
+		CRingBufferBase::SetPopCallback([PopCallback](void *pCurrent) {
+			PopCallback((T *)pCurrent);
+		});
+	}
 
 	T *Prev(T *pCurrent) { return (T *)CRingBufferBase::Prev(pCurrent); }
 	T *Next(T *pCurrent) { return (T *)CRingBufferBase::Next(pCurrent); }

src/game/client/components/console.cpp

@@ -208,6 +208,13 @@ CGameConsole::CInstance::CInstance(int Type)
 
 	m_IsCommand = false;
 
+	m_Backlog.SetPopCallback([this](CBacklogEntry *pEntry) {
+		if(pEntry->m_LineCount != -1)
+		{
+			m_NewLineCounter -= pEntry->m_LineCount;
+		}
+	});
+
 	m_Input.SetClipboardLineCallback([this](const char *pStr) { ExecuteLine(pStr); });
 
 	m_CurrentMatchIndex = -1;
@@ -236,7 +243,7 @@ void CGameConsole::CInstance::ClearBacklog()
 void CGameConsole::CInstance::UpdateBacklogTextAttributes()
 {
 	// Pending backlog entries are not handled because they don't have text attributes yet.
-	for(CInstance::CBacklogEntry *pEntry = m_Backlog.First(); pEntry; pEntry = m_Backlog.Next(pEntry))
+	for(CBacklogEntry *pEntry = m_Backlog.First(); pEntry; pEntry = m_Backlog.Next(pEntry))
 	{
 		UpdateEntryTextAttributes(pEntry);
 	}
@@ -244,27 +251,29 @@ void CGameConsole::CInstance::UpdateBacklogTextAttributes()
 
 void CGameConsole::CInstance::PumpBacklogPending()
 {
-	std::vector<CInstance::CBacklogEntry *> vpEntries;
 	{
 		// We must ensure that no log messages are printed while owning
 		// m_BacklogPendingLock or this will result in a dead lock.
 		const CLockScope LockScopePending(m_BacklogPendingLock);
-		for(CInstance::CBacklogEntry *pPendingEntry = m_BacklogPending.First(); pPendingEntry; pPendingEntry = m_BacklogPending.Next(pPendingEntry))
+		for(CBacklogEntry *pPendingEntry = m_BacklogPending.First(); pPendingEntry; pPendingEntry = m_BacklogPending.Next(pPendingEntry))
 		{
 			const size_t EntrySize = sizeof(CBacklogEntry) + pPendingEntry->m_Length;
 			CBacklogEntry *pEntry = m_Backlog.Allocate(EntrySize);
 			mem_copy(pEntry, pPendingEntry, EntrySize);
-			vpEntries.push_back(pEntry);
 		}
 
 		m_BacklogPending.Init();
 	}
 
+	// Update text attributes and count number of added lines
 	m_pGameConsole->Ui()->MapScreen();
-	for(CInstance::CBacklogEntry *pEntry : vpEntries)
+	for(CBacklogEntry *pEntry = m_Backlog.First(); pEntry; pEntry = m_Backlog.Next(pEntry))
 	{
-		UpdateEntryTextAttributes(pEntry);
+		if(pEntry->m_LineCount == -1)
-		m_NewLineCounter += pEntry->m_LineCount;
+		{
+			UpdateEntryTextAttributes(pEntry);
+			m_NewLineCounter += pEntry->m_LineCount;
+		}
 	}
 }
 
@@ -1133,7 +1142,7 @@ void CGameConsole::OnRender()
 		}
 
 		pConsole->PumpBacklogPending();
-		if(pConsole->m_NewLineCounter > 0)
+		if(pConsole->m_NewLineCounter != 0)
 		{
 			pConsole->UpdateSearch();
 
@@ -1143,6 +1152,8 @@ void CGameConsole::OnRender()
 				pConsole->m_BacklogCurLine += pConsole->m_NewLineCounter;
 				pConsole->m_BacklogLastActiveLine += pConsole->m_NewLineCounter;
 			}
+			if(pConsole->m_NewLineCounter < 0)
+				pConsole->m_NewLineCounter = 0;
 		}
 
 		// render console log (current entry, status, wrap lines)