From fba1e9fa61466b25e4611f65b0281e7bae4fa167 Mon Sep 17 00:00:00 2001
From: James Turner <james@flightgear.org>
Date: Wed, 21 Apr 2021 21:56:33 +0100
Subject: [PATCH] YASim: fix warnings from bind()

Add a version of fgUntie which is quiet, if the property does not
currently exist.
---
 src/FDM/YASim/YASim.cxx | 15 ++++++++++-----
 src/Main/fg_props.cxx   | 16 ++++++++++++++++
 src/Main/fg_props.hxx   |  4 ++++
 3 files changed, 30 insertions(+), 5 deletions(-)

diff --git a/src/FDM/YASim/YASim.cxx b/src/FDM/YASim/YASim.cxx
index 9e4b50ba0..1647ddca7 100644
--- a/src/FDM/YASim/YASim.cxx
+++ b/src/FDM/YASim/YASim.cxx
@@ -94,11 +94,16 @@ void YASim::bind()
 
     char buf[256];
     for(int i=0; i<_fdm->getAirplane()->getModel()->numThrusters(); i++) {
-        sprintf(buf, "/engines/engine[%d]/fuel-flow-gph", i);        fgUntie(buf);
-        sprintf(buf, "/engines/engine[%d]/rpm", i);                  fgUntie(buf);
-        sprintf(buf, "/engines/engine[%d]/mp-osi", i);               fgUntie(buf);
-        sprintf(buf, "/engines/engine[%d]/egt-degf", i);             fgUntie(buf);
-        sprintf(buf, "/engines/engine[%d]/oil-temperature-degf", i); fgUntie(buf);
+        sprintf(buf, "/engines/engine[%d]/fuel-flow-gph", i);
+        fgUntieIfDefined(buf);
+        sprintf(buf, "/engines/engine[%d]/rpm", i);
+        fgUntieIfDefined(buf);
+        sprintf(buf, "/engines/engine[%d]/mp-osi", i);
+        fgUntieIfDefined(buf);
+        sprintf(buf, "/engines/engine[%d]/egt-degf", i);
+        fgUntieIfDefined(buf);
+        sprintf(buf, "/engines/engine[%d]/oil-temperature-degf", i);
+        fgUntieIfDefined(buf);
     }
 }
 
diff --git a/src/Main/fg_props.cxx b/src/Main/fg_props.cxx
index 4679a752e..6218ac571 100644
--- a/src/Main/fg_props.cxx
+++ b/src/Main/fg_props.cxx
@@ -720,5 +720,21 @@ fgUntie(const char * name)
   }
 }
 
+void fgUntieIfDefined(const std::string& name)
+{
+    SGPropertyNode* node = globals->get_props()->getNode(name);
+    if (!node) {
+        return;
+    }
+
+    if (!node->isTied()) {
+        return;
+    }
+
+    if (!node->untie()) {
+        SG_LOG(SG_GENERAL, SG_WARN, "Failed to untie property " << name);
+    }
+}
+
 
 // end of fg_props.cxx
diff --git a/src/Main/fg_props.hxx b/src/Main/fg_props.hxx
index 894f69e4d..2ec24f770 100644
--- a/src/Main/fg_props.hxx
+++ b/src/Main/fg_props.hxx
@@ -716,6 +716,10 @@ extern void fgSetWritable (const char * name, bool state = true);
  */
 extern void fgUntie (const char * name);
 
+/**
+ @brfief variant of the above which doesn't warn if the property does not exist
+ */
+void fgUntieIfDefined(const std::string& name);
 
 /**
  * Tie a property to a pair of simple functions.