c++/2517: -O2 compilation appears to cause a memory leak when a string is added to a char[]

[knuteson@fnal.gov]

>Number:         2517
>Category:       c++
>Synopsis:       -O2 compilation appears to cause a memory leak when a string is added to a char[]
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Apr 09 08:56:02 PDT 2001
>Closed-Date:
>Last-Modified:
>Originator:     Bruce Knuteson
>Release:        unknown-1.0
>Organization:
>Environment:
mips-sgi-irix6.5
>Description:
-O2 compilation appears to cause a memory leak when a string is added to a char[]
>How-To-Repeat:
Compile the following with 'g++ -O2':

#include <string>
using namespace std;

int main()
{
  string s1="hi",s2;
  while(true)
    s2=s1+" there.";
  return(0);
}

and run while viewing memory usage using top.
The memory used quickly increases without bound.
>Fix:
I wish I knew . . . 
>Release-Note:
>Audit-Trail:
>Unformatted: