# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1276299742 -7200
# Node ID 171279c4c97a0caa76764012034beecefa4679eb
# Parent  1bb8c2609f1eea7ec3e95a087efefc575575c888
Fixed memory allocation for list fragments.

diff -r 1bb8c2609f1e -r 171279c4c97a lib/builtins.py
--- a/lib/builtins.py	Sat Jun 12 01:07:13 2010 +0200
+++ b/lib/builtins.py	Sat Jun 12 01:42:22 2010 +0200
@@ -157,7 +157,8 @@
                 self.append(arg)
 
     def __new__(self):
-        self._elements = None # defined in a native method
+        # Reserve space for a fragment reference.
+        self._elements = None
 
     def __getitem__(self, index): pass
     def __setitem__(self, index, value): pass
diff -r 1bb8c2609f1e -r 171279c4c97a rsvp.py
--- a/rsvp.py	Sat Jun 12 01:07:13 2010 +0200
+++ b/rsvp.py	Sat Jun 12 01:42:22 2010 +0200
@@ -449,7 +449,8 @@
 
     def MakeFragment(self):
         size = self.operand
-        addr = self._MakeFragment(size)
+        # Reserve twice the amount of space.
+        addr = self._MakeFragment(size, size * 2)
         # NOTE: Context is not relevant for fragments.
         self.value = DataValue(None, addr)
 
@@ -806,11 +807,10 @@
         self.save(addr, data.with_size(size))
         return addr
 
-    def _MakeFragment(self, size):
-        # Reserve twice the amount of space.
-        addr = self.new(size * 2)
+    def _MakeFragment(self, occupied, size):
+        addr = self.new(size)
         # Save the header, overriding the size.
-        self.save(addr, FragmentObject(size, size * 2))
+        self.save(addr, FragmentObject(occupied, size))
         return addr
 
     def _LoadAddressContextCond(self, context, ref, inst_ref):
diff -r 1bb8c2609f1e -r 171279c4c97a rsvplib.py
--- a/rsvplib.py	Sat Jun 12 01:07:13 2010 +0200
+++ b/rsvplib.py	Sat Jun 12 01:42:22 2010 +0200
@@ -261,13 +261,13 @@
         # Make a new sequence.
         # NOTE: Using an arbitrary size.
 
-        new_fragment = self.machine._MakeFragment(5)
+        new_fragment = self.machine._MakeFragment(1, 5) # include the header
 
         # Complete the list instance by saving the fragment reference.
+        # NOTE: This requires an attribute in the list structure.
 
         addr = list_value.ref + 1
         self.machine.save(addr, DataValue(None, new_fragment))
-        self.machine.result = DataValue(addr, addr)
 
     def builtins_list_getitem(self):
         frame = self.local_sp_stack[-1]
@@ -367,14 +367,14 @@
             # Make a new fragment, maintaining more space than currently
             # occupied in order to avoid reallocation.
 
-            new_fragment = self.machine._MakeFragment(header.allocated_size + 1)
+            new_fragment = self.machine._MakeFragment(header.occupied_size, header.occupied_size * 2)
 
             # Copy existing elements.
 
-            for i in range(1, header.allocated_size):
+            for i in range(1, header.occupied_size):
                 self.machine.save(new_fragment + i, self.machine.load(fragment.ref + i))
 
-            self.machine.save(new_fragment + header.allocated_size, arg_value)
+            self.machine.save(new_fragment + header.occupied_size, arg_value)
 
             # Set the new fragment in the object.
             # NOTE: The old fragment could be deallocated.