Tested on debian/amd64 with gdb 7.12/8.0/8.1/8.2
vgdb-error value changed from 0 to 999999
Breakpoint 1 at 0x........: file leak-tree.c, line 42.
-Breakpoint 2 at 0x........: file leak-tree.c, line 67.
+Breakpoint 2 at 0x........: file leak-tree.c, line 68.
Continuing.
Breakpoint 1, f () at leak-tree.c:42
42 t->l = mk(); // B
# insert break after the allocation of A
break leak-tree.c:42
# insert break after returning from function f
-break leak-tree.c:67
+break leak-tree.c:68
#
# continue till //1break:
continue