diff --git a/src/core/org/luaj/vm2/LoadState.java b/src/core/org/luaj/vm2/LoadState.java
index 6dc072db..5eb69fec 100644
--- a/src/core/org/luaj/vm2/LoadState.java
+++ b/src/core/org/luaj/vm2/LoadState.java
@@ -312,9 +312,8 @@ public class LoadState {
 		}
 		
 		n = loadInt();
-		f.upvalues = n>0? new Upvaldesc[n]: NOUPVALDESCS;
 		for ( int i=0; i<n; i++ )
-			f.upvalues[i] = new Upvaldesc(loadString(), false, i);
+			f.upvalues[i].name = loadString();
 	}
 
 	/** 
diff --git a/src/core/org/luaj/vm2/Upvaldesc.java b/src/core/org/luaj/vm2/Upvaldesc.java
index 28326c6c..c1e44974 100644
--- a/src/core/org/luaj/vm2/Upvaldesc.java
+++ b/src/core/org/luaj/vm2/Upvaldesc.java
@@ -24,7 +24,7 @@ package org.luaj.vm2;
 public class Upvaldesc {
 
 	/* upvalue name (for debug information) */
-	public final LuaString name;
+	public LuaString name;
 	
 	/* whether it is in stack */
 	public final boolean instack;
diff --git a/src/core/org/luaj/vm2/compiler/FuncState.java b/src/core/org/luaj/vm2/compiler/FuncState.java
index fc3f8352..85002009 100644
--- a/src/core/org/luaj/vm2/compiler/FuncState.java
+++ b/src/core/org/luaj/vm2/compiler/FuncState.java
@@ -279,26 +279,24 @@ public class FuncState extends LuaC {
 	// =============================================================
 
 	void nil(int from, int n) {
-		InstructionPtr previous;
-		if (this.pc > this.lasttarget) { /* no jumps to current position? */
-			if (this.pc == 0) { /* function start? */
-				if (from >= this.nactvar)
-					return; /* positions are already clean */
-			} else {
-				previous = new InstructionPtr(this.f.code, this.pc - 1);
-				if (GET_OPCODE(previous.get()) == OP_LOADNIL) {
-					int pfrom = GETARG_A(previous.get());
-					int pto = GETARG_B(previous.get());
-					if (pfrom <= from && from <= pto + 1) { /* can connect both? */
-						if (from + n - 1 > pto)
-							SETARG_B(previous, from + n - 1);
-						return;
-					}
-				}
+		final int code_prev = f.code[pc - 1];
+		if (pc > 0 && GET_OPCODE(code_prev) == OP_LOADNIL) {
+			int l = from + n - 1; /* last register to set nil */
+			int pfrom = GETARG_A(code_prev);
+			int pl = pfrom + GETARG_B(code_prev);
+			if ((pfrom <= from && from <= pl + 1)
+					|| (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */
+				if (pfrom < from)
+					from = pfrom; /* from = min(from, pfrom) */
+				if (pl > l)
+					l = pl; /* l = max(l, pl) */
+				InstructionPtr previous = new InstructionPtr(this.f.code, this.pc - 1);
+				SETARG_A(previous, from);
+				SETARG_B(previous, l - from);
+				return;
 			}
-		}
-		/* else no optimization */
-		this.codeABC(OP_LOADNIL, from, from + n - 1, 0); 
+		}  /* else go through */
+		this.codeABC(OP_LOADNIL, from, n - 1, 0); 
 	}
 
 
diff --git a/src/core/org/luaj/vm2/compiler/LexState.java b/src/core/org/luaj/vm2/compiler/LexState.java
index 6d270d23..fc3ef1aa 100644
--- a/src/core/org/luaj/vm2/compiler/LexState.java
+++ b/src/core/org/luaj/vm2/compiler/LexState.java
@@ -1065,7 +1065,6 @@ public class LexState {
 	}
 
 	void open_func (FuncState fs, BlockCnt bl) {
-		  Prototype f = new Prototype();
 		  fs.prev = this.fs;  /* linked list of funcstates */
 		  fs.ls = this;
 		  this.fs = fs;
@@ -1080,7 +1079,8 @@ public class LexState {
 		  fs.nactvar = 0;
 		  fs.firstlocal = dyd.n_actvar;
 		  fs.bl = null;
-		  f.maxstacksize = 2;  /* registers 0/1 are always valid */
+		  fs.f.source = this.source;
+		  fs.f.maxstacksize = 2;  /* registers 0/1 are always valid */
 		  fs.enterblock(bl,  false);
 	}