Remove default empty value from bare version of executeFromSelfReg. Update documentation to match.

Author: novamon

data/shared/src/main/scala/sigma/ast/SigmaPredef.scala

@@ -432,31 +432,16 @@ object SigmaPredef {
             throw new InvalidArguments(s"Invalid register specified $id")
           }
 
-          val d : Option[Value[rtpe.type]] = rtpe match {
-            case SInt       => Some(IntConstant(0).asValue)
-            case SBoolean   => Some(BooleanConstant(false).asValue)
-            case SByte      => Some(ByteConstant(0).asValue)
-            case SLong      => Some(LongConstant(0L).asValue)
-            case SBigInt    => Some(BigIntConstant(0).asValue)
-            case SSigmaProp => Some(SigmaPropConstant(CSigmaProp(false)).asValue)
-            case c: SCollection[a] =>
-              implicit val elemRType: RType[a#WrappedType] = asType(stypeToRType(c.elemType))
-              implicit val elemCT: ClassTag[a#WrappedType] = elemRType.classTag
-              Some(CollectionConstant(Colls.fromArray(elemRType.emptyArray), c.elemType).asValue)
-            case _ => None
-          }
-
           val r: RegisterId = org.ergoplatform.ErgoBox.registerByIndex(idx)
-          mkDeserializeRegister[rtpe.type](r, rtpe, d)
+          mkDeserializeRegister[rtpe.type](r, rtpe, None)
         }),
       OperationInfo(DeserializeRegister,
         """Extracts SELF register as \lst{Coll[Byte]}, deserializes it to script
           | and then executes this script in the current context.
           | The original \lst{Coll[Byte]} of the script is available as \lst{SELF.getReg[Coll[Byte]](id)}.
           | Type parameter \lst{T} result type of the deserialized script.
           | Throws an exception if the actual script type doesn't conform to \lst{T}.
-          | Returns a result of the script execution in the current context or an empty value
-          | of type \lst{T} when the specified register is unavailable
+          | Returns a result of the script execution in the current context
         """.stripMargin,
         Seq(ArgInfo("id", "identifier of the register")))
     )

docs/LangSpec.md

@@ -1036,9 +1036,8 @@ def executeFromVar[T](id: Byte): T
  * 
  * Extracts, deserializes and executes a script contained in the SELF register 
  * indicated by id. Returns the result of the script execution in the current context
- * or and empty value, if the register is unavailable. An exception is thrown if the result 
- * type of the execution doesn't conform to the return type specified and if an invalid 
- * register is specified.
+ * An exception is thrown if the result type of the execution doesn't conform to the
+ * return type specified and if an invalid register is specified.
  * 
  * @param id register id holding the serialized script to execute
  * @tparam T expected type of the register and return type.

sc/shared/src/test/scala/sigmastate/utxo/BasicOpsSpecification.scala

@@ -355,30 +355,6 @@ class BasicOpsSpecification extends CompilerTestingCommons
     )
   }
 
-  property("executeFromSelfReg - ScriptReduction") {
-    assertExceptionThrown(
-      test("executeFromSelfReg", env, ext,
-        "{ val ba = executeFromSelfReg[Coll[Byte]](4); ba.size == 2 }",
-        null,
-        true,
-        additionalRegistersOpt = Some(Map())
-      ),
-      e => {
-        val r = rootCause(e)
-        r.isInstanceOf[InterpreterException] && r.getMessage == "Script reduced to false"
-      }
-    )
-  }
-
-  property("executeFromSelfReg - ForceDefault") {
-    test("executeFromSelfReg", env, ext,
-      "{ executeFromSelfReg[Int](4) == 0 }",
-      null,
-      true,
-      additionalRegistersOpt = Some(Map())
-    )
-  }
-
   property("executeFromSelfReg - InvalidRegister") {
     assertExceptionThrown(
       test("executeFromSelfReg", env, ext,