From 56c4ba67c6249f4f8779ccf710ceb650c7c81acf Mon Sep 17 00:00:00 2001
From: ehofman <ehofman>
Date: Sat, 9 May 2009 11:34:28 +0000
Subject: [PATCH]  * Add a function to create a node after the laste node with
 the same name    (this frees the xml property loader from keeping track of
 the number of     nodes with the same name that have already been added to
 the property     tree).  * make some small code cleanups at the core of the
 property tree.

---
 simgear/props/props.cxx | 49 ++++++++++++++++++++++++++++++++++++-----
 simgear/props/props.hxx |  4 ++++
 2 files changed, 47 insertions(+), 6 deletions(-)

diff --git a/simgear/props/props.cxx b/simgear/props/props.cxx
index f73e773e..83b586c0 100644
--- a/simgear/props/props.cxx
+++ b/simgear/props/props.cxx
@@ -229,11 +229,13 @@ parse_path (const string &path, vector<PathComponent> &components)
 static char *
 copy_string (const char * s)
 {
-				// FIXME: potential buffer overflow.
-				// For some reason, strnlen and
-				// strncpy cause all kinds of crashes.
-  char * copy = new char[strlen(s) + 1];
-  strcpy(copy, s);
+  unsigned long int slen = strlen(s);
+  char * copy = new char[slen + 1];
+
+  // the source string length is known so no need to check for '\0'
+  // when copying every single character
+  memcpy(copy, s, slen);
+  *(copy + slen) = '\0';
   return copy;
 }
 
@@ -252,12 +254,32 @@ find_child (const char * name, int index, const vector<SGPropertyNode_ptr>& node
   int nNodes = nodes.size();
   for (int i = 0; i < nNodes; i++) {
     SGPropertyNode * node = nodes[i];
-    if (compare_strings(node->getName(), name) && node->getIndex() == index)
+
+    // searching for a mathing index is a lot less time consuming than
+    // comparing two strings so do that first.
+    if (node->getIndex() == index && compare_strings(node->getName(), name))
       return i;
   }
   return -1;
 }
 
+/**
+ * Locate the last child node with a given name.
+*/
+static int
+find_last_child (const char * name, const vector<SGPropertyNode_ptr>& nodes)
+{
+  int nNodes = nodes.size();
+  int pos = -1;
+
+  for (int i = 0; i < nNodes; i++) {
+    SGPropertyNode * node = nodes[i];
+    if (compare_strings(node->getName(), name))
+      pos++;
+  }
+  return pos;
+}
+
 
 /**
  * Locate another node, given a relative path.
@@ -824,6 +846,21 @@ SGPropertyNode::getAliasTarget () const
   return (_type == ALIAS ? _value.alias : 0);
 }
 
+/**
+ * create a non-const child by name after the last node with the same name.
+ */
+SGPropertyNode *
+SGPropertyNode::addChild (const char * name)
+{
+  int pos = find_last_child(name, _children);
+
+  SGPropertyNode_ptr node;
+  node = new SGPropertyNode(name, ++pos, this);
+  _children.push_back(node);
+  fireChildAdded(node);
+  return node;
+}
+
 
 /**
  * Get a non-const child by index.
diff --git a/simgear/props/props.hxx b/simgear/props/props.hxx
index d25637e0..cc1ed537 100644
--- a/simgear/props/props.hxx
+++ b/simgear/props/props.hxx
@@ -622,6 +622,10 @@ public:
     return (getChild(name, index) != 0);
   }
 
+  /**
+   * Create a child node after the last node with the same name.
+   */
+  SGPropertyNode * addChild (const char * name);
 
   /**
    * Get a child node by name and index.
-- 
2.39.5