Changelog for pkgconf: 3.0.3 -> 3.0.4
Source: NEWS

Changes from 3.0.3 to 3.0.4:
----------------------------

* Fix a crash (stack overflow) triggered by a crafted .pc file containing a
  self-referential fragment variable, such as `x=$${x}` referenced from Cflags.
  Fragment variables are now evaluated only once while re-splitting.  Found
  through fuzzing.

* Fix over-escaping of variable values containing backslash-escaped whitespace,
  such as paths quoted with `printf %q`.  Such a value was stored with its
  escapes intact and then escaped a second time when rendered into a fragment,
  producing output like `-L/a\\\ dir`.  This broke meson's test suite, which
  uses paths with spaces to stay Windows-safe.

* Fix mangled and duplicated -L/-I paths on Windows when PKG_CONFIG_SYSROOT_DIR
  and PKG_CONFIG_LIBDIR are set.  Path separators are now normalized to forward
  slashes for all runtime-injected paths (sysroot, build root, search paths and
  pcfiledir), so that sysroot matching and injection operate on a consistent
  basis.

* Fix `--define-prefix` dropping a path separator when the redefined prefix ends
  with a trailing slash, and only rewrite a package's directories when they match
  the original prefix on a path component boundary.

* Fix single-package queries returning results drawn from more than the requested
  module, by restoring the package limit that was lost during a refactor of the
  query builder.