Completely irrelevant. Nothing will reference that .la file.
might still be invalid for a reason, but not invalid for that reason:
that file refer to png14 as a dependency lib.
# libgstpango.la - a libtool library file
# Generated by ltmain.sh (GNU libtool) 2.2.6b Debian-2.2.6b-2
# Please DO NOT delete this file!
# It is necessary for linking the library.
# The name that we can dlopen(3).
# Names of this library.
library_names='libgstpango.so libgstpango.so libgstpango.so'
# The name of the static archive.
# Linker flags that can not go in dependency_libs.
# Libraries that this one depends upon.
dependency_libs=' -L/usr/lib -lgstvideo-0.10 -lgstbase-0.10 -lgstcontroller-0.10 -lgstreamer-0.10 -lxml2 -licui18n -licuuc -licudata -lpangocairo-1.0 -lcairo -lpangoft2-1.0 -lpango-1.0 -lgobject-2.0 -lgmodule-2.0 -lpixman-1 -lfontconfig -lfreetype -lexpat -lpng14 -lxcb-shm -lxcb-render -lXrender -lX11 -lxcb -lXau -lXdmcp -lz -lGL -lEGL -lm -lgthread-2.0 -ldl -lpthread -lglib-2.0 -lrt'
# Names of additional weak libraries provided by this library
# Version information for libgstpango.
# Is this an already installed library?
# Should we warn about portability when linking against -modules?
# Files to dlopen/dlpreopen
# Directory that this library needs to be installed in:
Just to be clear, in case this is a simple misunderstanding - I meant that nothing will reference /usr/lib/gstreamer-0.10/libgstpango.la, not that it doesn't reference libpng in it.
As such, if you understand what libtool file are and how they work, this is INVALID.
Stéphane, Leio is right with this one. Other packages propably won't look into the /usr/lib/gstreamer-0.10/ directory at all, so while the file is redudant and should get removed anyway, it's propably harmless.