From f331ae8f818a65ba0e61d14b69d1f611c45a696a Mon Sep 17 00:00:00 2001
From: Jonathan G Rennison <j.g.rennison@gmail.com>
Date: Sun, 28 Apr 2019 11:10:35 +0100
Subject: [PATCH] Progsig: Fix error return path in CmdModifySignalInstruction

---
 src/programmable_signals.cpp | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/programmable_signals.cpp b/src/programmable_signals.cpp
index d366936fe4..a353e85e54 100644
--- a/src/programmable_signals.cpp
+++ b/src/programmable_signals.cpp
@@ -609,7 +609,9 @@ CommandCost CmdModifySignalInstruction(TileIndex tile, DoCommandFlag flags, uint
 						} else if (f == SCF_VALUE) {
 							if (!exec) return CommandCost();
 							vc->value = val;
-						} else CommandCost(STR_ERR_PROGSIG_INVALID_CONDITION_FIELD);
+						} else {
+							return_cmd_error(STR_ERR_PROGSIG_INVALID_CONDITION_FIELD);
+						}
 					} break;
 
 					case PSC_SIGNAL_STATE: {