IMPORTANT: backwards-incompatible change to properties.

The useDefault argument for the SGPropertyNode::tie(...) methods will
invoke the setter only when there is already a property value defined;
previously, the setter was always invoked, with a default value if
necessary.

diff --git a/simgear/misc/props.cxx b/simgear/misc/props.cxx
index 359519efc58cc4acf702ea4d9fc6a512bc364742..ebad665caa249234efb43c3dc55fe3a7c7352107 100644 (file)
--- a/simgear/misc/props.cxx
+++ b/simgear/misc/props.cxx
@@ -1117,6 +1117,7 @@ SGPropertyNode::tie (const SGRawValue<bool> &rawValue, bool useDefault)
   if (_type == ALIAS || _tied)
     return false;
 
+  useDefault = useDefault && hasValue();
   bool old_val = false;
   if (useDefault)
     old_val = getBoolValue();
@@ -1138,6 +1139,7 @@ SGPropertyNode::tie (const SGRawValue<int> &rawValue, bool useDefault)
   if (_type == ALIAS || _tied)
     return false;
 
+  useDefault = useDefault && hasValue();
   int old_val = 0;
   if (useDefault)
     old_val = getIntValue();
@@ -1159,6 +1161,7 @@ SGPropertyNode::tie (const SGRawValue<long> &rawValue, bool useDefault)
   if (_type == ALIAS || _tied)
     return false;
 
+  useDefault = useDefault && hasValue();
   long old_val = 0;
   if (useDefault)
     old_val = getLongValue();
@@ -1180,6 +1183,7 @@ SGPropertyNode::tie (const SGRawValue<float> &rawValue, bool useDefault)
   if (_type == ALIAS || _tied)
     return false;
 
+  useDefault = useDefault && hasValue();
   float old_val = 0.0;
   if (useDefault)
     old_val = getFloatValue();
@@ -1201,6 +1205,7 @@ SGPropertyNode::tie (const SGRawValue<double> &rawValue, bool useDefault)
   if (_type == ALIAS || _tied)
     return false;
 
+  useDefault = useDefault && hasValue();
   double old_val = 0.0;
   if (useDefault)
     old_val = getDoubleValue();
@@ -1223,6 +1228,7 @@ SGPropertyNode::tie (const SGRawValue<string> &rawValue, bool useDefault)
   if (_type == ALIAS || _tied)
     return false;
 
+  useDefault = useDefault && hasValue();
   string old_val;
   if (useDefault)
     old_val = getStringValue();