[ns] [bug] rtable problem

[Frank Duerr]

[Bug Report]

-----------------------------
Category:  Other
Package:   ns 2..27
OS:        Linux
Environment Variables:
LD_LIBRARY_PATH=
TCL_LIBRARY=
TK_LIBRARY=


-----------------------------
Description:

Description of Problem:

In the method AddEntry in file ns-2.27/dsdv/rtable.cc the following code (line 102) is error-prone:

  while (i >= max)
	  rtab[i+1] = rtab[i--];
 
Depending on the compiler used and its optimizations, the second line is equivalent to 

foo = rtab[i--];
rtab[i+1] = foo; // That means, e.g. rtab[42] = rtab[42]

which is clearly not intended. gcc compiles this code "correctly", but for instance the Intel Compiler icc8 for Linux compiles the "wrong" code.

Solution: Use this code instead
 
  while (i >= max) {
	  rtab[i+1] = rtab[i];
	  i--;
  }

How Easily Reproducible:
(e.g. every time, intermittent, once only, etc.)

Every time using the Intel compiler icc8 for Linux.