Previously gst_buffer_list_foreach() could modify (drop or replace)
buffers in non-writable lists, which could cause all kinds of problems
if other code also has a reference to the list and assumes that it stays
the same.
https://bugzilla.gnome.org/show_bug.cgi?id=796692
gst_buffer_list_new_sized(0) will cause an underflow in a calculation
which then makes it try to allocate huge amounts of memory, which
may lead to aborts.
https://bugzilla.gnome.org/show_bug.cgi?id=795758
Adding a buffer to the end of a GstBufferList is supposed to be a fast
operation, but it was not since the iterator does not advance its
nextpointer when adding buffers and GList does not have a tail pointer.
Using a GQueue to store the buffers makes it easier to add buffers to
the end of the list and this operation will now be much more efficient.
Adding an entire GList of buffers using
gst_buffer_list_iterator_add_list() will however have to iterate over
the list being added to be able to update the tail pointer in the
GQueue.
This changes some APIs in compatible ways:
- Some functions now take "const char *" arguments, not "char *"
- Some structs now have "conts char *" members, not "char *"
The changes may cause warnings when compiling with the right warning
flags. You've been warned.
Also adds -Wwrite-strings as a warning flag in configure.ac.
https://bugzilla.gnome.org/show_bug.cgi?id=611692
Add new method to iterate a bufferlist without having to allocate an iterator.
Add convenience method for getting an item from the list based on the group and
index.
Remove redundant _do_data callback and method.
Update unit-tests and add some more for the new methods.
