Allow empty assignment in for-loop

For loops with no assignment are no longer syntax errors. For example,
this is now valid:

    for ( ; i < 10; i++) { ... }

Corresponding changes to lsl.{lexer,parser} in r99 in opensim-libs.

Fixes Mantis #2501. Fixes Mantis #2884.

1 files changed, 15 insertions, 3 deletions

diff --git a/OpenSim/Region/ScriptEngine/Shared/CodeTools/LSL2CSCodeTransformer.cs b/OpenSim/Region/ScriptEngine/Shared/CodeTools/LSL2CSCodeTransformer.cs
index 0dddede..cacb8be 100644
--- a/OpenSim/Region/ScriptEngine/Shared/CodeTools/LSL2CSCodeTransformer.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/CodeTools/LSL2CSCodeTransformer.cs
@@ -92,10 +92,22 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
 
             for (int i = 0; i < s.kids.Count; i++)
             {
-                if (!(s is Assignment || s is ArgumentDeclarationList) && s.kids[i] is Declaration)
-                    AddImplicitInitialization(s, i);
+                // It's possible that a child is null, for instance when the
+                // assignment part in a for-loop is left out, ie:
+                //
+                //     for ( ; i < 10; i++)
+                //     {
+                //         ...
+                //     }
+                //
+                // We need to check for that here.
+                if (null != s.kids[i])
+                {
+                    if (!(s is Assignment || s is ArgumentDeclarationList) && s.kids[i] is Declaration)
+                        AddImplicitInitialization(s, i);
 
-                TransformNode((SYMBOL) s.kids[i]);
+                    TransformNode((SYMBOL) s.kids[i]);
+                }
             }
         }