libstdc++/3: Segmentation Faults in substr() and string()

[bmosher@csc.com]

>Number:         3
>Category:       libstdc++
>Synopsis:       Segmentation Faults in substr() and string()
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Wed Aug 25 11:47:00 PDT 1999
>Closed-Date:
>Last-Modified:
>Originator:     Bob Mosher, Computer Sciences Corporation (210)733-4825
>Release:        2.8.1, 2.8.1.1
>Organization:
>Environment:
SPARC Ultra 60, Solaris 2.6, gcc 2.8.1
>Description:
Example One ( segfault in substr() ):
  This segfault happens after correctly handling five other
  substr() calls in three separate source code modules.
  I've tried:
    - string s = current_line(21,4);
    - string s = current_line(21);
    - string s(current_line,21,4);
    - string s(current_line,21);
    - removing and reinstalling the compiler and associated libraries;
    - replacing the RAM;
  Nothing helps.

  Source code snippet:
  ulong
  rta:: ParseConnectionNumber(string current_line )
  {
    string s = current_line;
    unsigned long connection_number = 0;

    string cnumber = s.substr(21);  // segfault here
  
    return connection_number;
  }

  Error message reported by gdb:
  Program received signal SIGSEGV, Segmentation fault.
  0x1bbe8 in basic_string<char, string_char_traits<char>, __default_alloc_template<false, 0> >::replace (this=0xefffefc8, 
pos=0, n1=0, s=0xa6d25 " 157", n2=4) at stl/stl_alloc.h:407
stl/stl_alloc.h:407: No such file or directory.

stl_alloc.h is present and I had "-I/usr/local/include/g++"
in the makefile.



Example Two ( segfault in string() ):
  If I comment out the offending line in Example One, Example Two appears
  in a different code module.  The while() loop correctly processes 
  eleven lines of text before segfaulting on the twelfth, which is a 
  blank line. Of the eleven lines correctly processed, two were blank.
  You'll note the error messages are nearly identical.

  Source code snippet:
  Parse44():
    int i = 24;
    while(!found)
      {
        fin.getline( buffer, LINELENGTH, '\n' );
        cout << "Parse44() buffer[" << i << "] = " << buffer << endl;
        str = string(buffer);   // segfault here
        cout << "Parse44() str        = " << str << endl;
      }

  Error message reported by gdb:
  Program received signal SIGSEGV, Segmentation fault.
0x1bb58 in basic_string<char, string_char_traits<char>, __default_alloc_template<false, 0> >::replace (this=0xeffff050, 
pos=0, n1=0, s=0xeffff170 "", n2=0) at stl/stl_alloc.h:407
stl/stl_alloc.h:407: No such file or directory.

>How-To-Repeat:
I wish I could keep it from repeating.
>Fix:
Not a clue.
>Release-Note:
>Audit-Trail:
>Unformatted: