Bugfix: Allocate empty array.

libsolidity/codegen/CompilerUtils.h

@@ -104,6 +104,7 @@ public:
 	);
 
 	/// Zero-initialises (the data part of) an already allocated memory array.
+	/// Length has to be nonzero!
 	/// Stack pre: <length> <memptr>
 	/// Stack post: <updated_memptr>
 	void zeroInitialiseMemoryArray(ArrayType const& _type);

libsolidity/codegen/ExpressionCompiler.cpp

@@ -792,15 +792,18 @@ bool ExpressionCompiler::visit(FunctionCall const& _functionCall)
 			utils().storeFreeMemoryPointer();
 			// Stack: memptr requested_length
 
+			// Check if length is zero
+			m_context << Instruction::DUP1 << Instruction::ISZERO;
+			auto skipInit = m_context.appendConditionalJump();
+
 			// We only have to initialise if the base type is a not a value type.
 			if (dynamic_cast<ReferenceType const*>(arrayType.baseType().get()))
 			{
 				m_context << Instruction::DUP2 << u256(32) << Instruction::ADD;
 				utils().zeroInitialiseMemoryArray(arrayType);
-				m_context << Instruction::POP;
 			}
-			else
-				m_context << Instruction::POP;
+			m_context << skipInit;
+			m_context << Instruction::POP;
 			break;
 		}
 		default: