Memory leak in g_string_sized_new()?

[Ronald Roth <rroth uiuc edu>]

Hi, all

While hunting for mem leaks in my program, I noticed that memprof was
reporting that a call to g_string_sized_new(str_size) was returning a
string whose "allocated_len" field was HALF of the amount of memory that
memprof said was allocated in that call.  Then, upon calling g_string_free
on the same string, with free_segment=TRUE, only "allocated_len" bytes were
free.  So, I can see no way to free the remaining memory!  Has anyone else
experienced this?  I can reproduce the problem on my computer with the
following test program, using memprof and noting the total allocated bytes
between the getchar() function calls.

#include <glib.h>
#include <stdio.h>

int main() {
        GString *temp;
        int size=5;

        temp=g_string_new(NULL);
        printf("About to allocate string\n");
        getchar();
        temp=g_string_sized_new(size);
        getchar();
        printf("temp size: %i alloc:%i\n", temp->len, temp->allocated_len);
        printf("About to free string.\n");
        getchar();
        g_string_free(temp, TRUE);
        return 0;
}

When I run this with "memprof ./test" I get the following results:
At the first getchar() call: Memprof reports 2236 bytes allocated.

Second getchar() call: 2252 bytes (Just called g_string_sized_new()) 16
bytes were allocated. (presumably to the GString "temp")

Third getchar() call: 2252 bytes, program reports temp->allocated_len=8.

Fourth getchar() call: 2244 bytes, (just called g_string_free()) 8 bytes
were freed.

As you can see, 8 bytes got leaked.  Could someone explain what is going
on?  Have I found a bug?  Or am I fooling myself? Or is memprof lying to me?

I have glib version 2.0.7.

Thanks!

-Ron Roth