Use brtrue as loop condition only if one of the destinations is not in the loop

ICSharpCode.Decompiler/ILAst/ILAstOptimizer.cs

@@ -464,7 +464,16 @@ namespace ICSharpCode.Decompiler.ILAst
 					ILExpression condExpr;
 					ILLabel trueLabel;
 					ILLabel falseLabel;
-					if(basicBlock.MatchBrTure(out condExpr, out trueLabel, out falseLabel)) {
+					if(basicBlock.MatchBrTure(out condExpr, out trueLabel, out falseLabel))
+					{
+						ControlFlowNode trueTarget;
+						labelToCfNode.TryGetValue(trueLabel, out trueTarget);
+						ControlFlowNode falseTarget;
+						labelToCfNode.TryGetValue(falseLabel, out falseTarget);
+					
+						if ((!loopContents.Contains(trueTarget) && loopContents.Contains(falseTarget)) ||
+						    (loopContents.Contains(trueTarget) && !loopContents.Contains(falseTarget)) )
+						{
 							loopContents.RemoveOrThrow(node);
 							scope.RemoveOrThrow(node);
 							
@@ -494,7 +503,11 @@ namespace ICSharpCode.Decompiler.ILAst
 								},
 								FallthoughGoto = null
 							});
-					} else {
+						}
+					}
+					
+					// Fallback method: while(true)
+					if (scope.Contains(node)) {
 						result.Add(new ILBasicBlock() {
 						    EntryLabel = new ILLabel() { Name = "Loop_" + (nextLabelIndex++) },
 							Body = new List<ILNode>() {