[Bug libc/5666] New: when getline fails it still allocates a buffer

["werner_hahn at yahoo dot de" <sourceware-bugzilla at sourceware dot org>]

This may be a documentation issue.

When passing the getline function a NULL pointer as a buffer it is so kind to 
allocate the needed memory. However when you reach for example EOF and the 
function returns -1 a buffer of length 120 bytes is allocated anyway which must 
be freed manually or else is lost. It took me quite some time to find out why 
valgrind always told me of 120 lost bytes. The documentation does not mention 
this and so I never suspected this function to be the memory leak.

As getline just functions as a wrapper around getdelim the issue should apply 
to that as well.

I give a quick example:

char *line = NULL;
unsigned int count = 0;
count = getline(&line, &count, file_descriptor);
if(count == -1) // now line points to 120 bytes of junk
{
  free(line); // without this free the buffer pointed to by line is lost
  return NULL;
}

-- 
           Summary: when getline fails it still allocates a buffer
           Product: glibc
           Version: 2.3.6
            Status: NEW
          Severity: normal
          Priority: P2
         Component: libc
        AssignedTo: drepper at redhat dot com
        ReportedBy: werner_hahn at yahoo dot de
                CC: glibc-bugs at sources dot redhat dot com


http://sourceware.org/bugzilla/show_bug.cgi?id=5666

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