* when the stack size is overestimated so much that it's larger than the

    stack pointer (can happen for externally started threads), truncate it
    to a legal value (should stop crashes when enabling stack checking on
    iOS 6)

git-svn-id: trunk@23320 -

rtl/bsd/system.pp

@@ -314,7 +314,12 @@ begin
 end;
 
 function CheckInitialStkLen(stklen : SizeUInt) : SizeUInt;
+var
+  stackpointer: ptruint;
 begin
+  stackpointer := (ptruint(sptr) + 4095) and not(4095);
+  if stklen > stackpointer then
+    stklen := stackpointer-4096;
   result := stklen;
 end;