From acbe3a191e7228816046948ba36de16d73b55c32 Mon Sep 17 00:00:00 2001
From: Randy Heit <rheit@zdoom.fake>
Date: Tue, 11 Dec 2007 03:29:31 +0000
Subject: [PATCH] - Fixed: Redefining a decal did not rebind any old references
 to the decal, so   they would be left pointing at invalid data.

SVN r594 (trunk)
---
 docs/rh-log.txt    |  2 ++
 src/decallib.cpp   | 27 +++++++++++++++++++++++++++
 src/decallib.h     |  3 +++
 src/weightedlist.h | 16 ++++++++++++++++
 4 files changed, 48 insertions(+)

diff --git a/docs/rh-log.txt b/docs/rh-log.txt
index db1722f732..410185320b 100644
--- a/docs/rh-log.txt
+++ b/docs/rh-log.txt
@@ -1,4 +1,6 @@
 December 10, 2007
+- Fixed: Redefining a decal did not rebind any old references to the decal, so
+  they would be left pointing at invalid data.
 - Fixed some more GCC warnings.
 - Updated project files for nasm 2.0, which is now named nasm.exe for the
   Windows version, rather than nasmw.exe. Also fixed the annoying new warnings
diff --git a/src/decallib.cpp b/src/decallib.cpp
index 25cb29db51..e7163820f3 100644
--- a/src/decallib.cpp
+++ b/src/decallib.cpp
@@ -66,6 +66,10 @@ class FDecalGroup : public FDecalBase
 public:
 	FDecalGroup () : Choices (pr_decalchoice) {}
 	const FDecalTemplate *GetDecal () const;
+	void ReplaceDecalRef (FDecalBase *from, FDecalBase *to)
+	{
+		Choices.ReplaceValues(from, to);
+	}
 	void AddDecal (FDecalBase *decal, WORD weight)
 	{
 		Choices.AddEntry (decal, weight);
@@ -301,6 +305,14 @@ const FDecalTemplate *FDecalBase::GetDecal () const
 	return NULL;
 }
 
+void FDecalTemplate::ReplaceDecalRef(FDecalBase *from, FDecalBase *to)
+{
+	if (LowerDecal == from)
+	{
+		LowerDecal = to;
+	}
+}
+
 FDecalLib::FDecalLib ()
 {
 	Root = NULL;
@@ -828,6 +840,17 @@ void FDecalLib::ParseCombiner ()
 	}
 }
 
+void FDecalLib::ReplaceDecalRef (FDecalBase *from, FDecalBase *to, FDecalBase *root)
+{
+	if (root == NULL)
+	{
+		return;
+	}
+	ReplaceDecalRef (from, to, root->Left);
+	ReplaceDecalRef (from, to, root->Right);
+	root->ReplaceDecalRef (from, to);
+}
+
 void FDecalLib::AddDecal (const char *name, BYTE num, const FDecalTemplate &decal)
 {
 	FDecalTemplate *newDecal = new FDecalTemplate;
@@ -873,6 +896,10 @@ void FDecalLib::AddDecal (FDecalBase *decal)
 	}
 	else
 	{ // Yes, replace the old one.
+		// If this decal has been used as the lowerdecal for another decal,
+		// be sure and update the lowerdecal to use the new decal.
+		ReplaceDecalRef(node, decal, Root);
+
 		decal->Left = node->Left;
 		decal->Right = node->Right;
 		*prev = decal;
diff --git a/src/decallib.h b/src/decallib.h
index 6793a694f6..e1cc4bf1db 100644
--- a/src/decallib.h
+++ b/src/decallib.h
@@ -52,6 +52,7 @@ class FDecalBase
 	friend class FDecalLib;
 public:
 	virtual const FDecalTemplate *GetDecal () const;
+	virtual void ReplaceDecalRef (FDecalBase *from, FDecalBase *to) = 0;
 	
 protected:
 	FDecalBase ();
@@ -71,6 +72,7 @@ public:
 
 	void ApplyToDecal (DBaseDecal *actor, side_s *wall) const;
 	const FDecalTemplate *GetDecal () const;
+	void ReplaceDecalRef (FDecalBase *from, FDecalBase *to);
 
 	fixed_t ScaleX, ScaleY;
 	DWORD ShadeColor;
@@ -104,6 +106,7 @@ private:
 	static void DelTree (FDecalBase *root);
 	static FDecalBase *ScanTreeForNum (const BYTE num, FDecalBase *root);
 	static FDecalBase *ScanTreeForName (const char *name, FDecalBase *root);
+	static void ReplaceDecalRef (FDecalBase *from, FDecalBase *to, FDecalBase *root);
 	FTranslation *GenerateTranslation (DWORD start, DWORD end);
 	void AddDecal (const char *name, BYTE num, const FDecalTemplate &decal);
 	void AddDecal (FDecalBase *decal);
diff --git a/src/weightedlist.h b/src/weightedlist.h
index 38e1d2fb6d..0e4294e842 100644
--- a/src/weightedlist.h
+++ b/src/weightedlist.h
@@ -66,6 +66,7 @@ class TWeightedList
 
 		void AddEntry (T value, WORD weight);
 		T PickEntry () const;
+		void ReplaceValues (T oldval, T newval);
 
 	private:
 		Choice<T> *Choices;
@@ -148,3 +149,18 @@ void TWeightedList<T>::RecalcRandomVals ()
 		choice->RandomVal = (BYTE)(randVal * 255.0);
 	}
 }
+
+// Replace all values that match oldval with newval
+template<class T>
+void TWeightedList<T>::ReplaceValues(T oldval, T newval)
+{
+	Choice<T> *choice;
+
+	for (choice = Choices; choice != NULL; choice = choice->Next)
+	{
+		if (choice->Value == oldval)
+		{
+			choice->Value = newval;
+		}
+	}
+}