Require gettext >= 0.18.3; remove GP_GETTEXT_HACK

This requires gettext version 0.18.3 or later, and it removes
the GP_GETTEXT_HACK which used to generate a po/Makevars file
from the po/Makevers.template.

gettext 0.18.3 is the same gettext version requirement
as libexif uses.

gettext 0.18.3 has been released 2013-07-07, which is
a similar timeframe of the autoconf, automake and libtool
releases we require.

If you ever need to build a post 2021 libgphoto2 from
git on a system with pre 0.18.3 gettext, you can can
always prepare a tarball using "make dist" on a system
with gettext 0.18.3 or later, and build that tarball
on the older machine.

Not generating the po/Makevars file any more means that
we need additional consistency checks for the parts of
po/Makevars which cannot be derived from the Autoconf
standard set of AC_SUBST()ed Makefile.in variables.

1 files changed, 53 insertions, 0 deletions

diff --git a/po/Makevars b/po/Makevars
new file mode 100644
index 000000000..fed054ec5
--- /dev/null
+++ b/po/Makevars
@@ -0,0 +1,53 @@
+# Makefile variables for PO directory in any package using GNU gettext.
+
+# Usually the message domain is the same as the package name.
+DOMAIN = libgphoto2-6
+
+# These two variables depend on the location of this directory.
+subdir = po
+top_builddir = ..
+
+# These options get passed to xgettext.
+XGETTEXT_OPTIONS = --keyword=_ --keyword=N_
+
+# This is the copyright holder that gets inserted into the header of the
+# $(DOMAIN).pot file.  Set this to the copyright holder of the surrounding
+# package.  (Note that the msgstr strings, extracted from the package's
+# sources, belong to the copyright holder of the package.)  Translators are
+# expected to transfer the copyright for their translations to this person
+# or entity, or to disclaim their copyright.  The empty string stands for
+# the public domain; in this case the translators are expected to disclaim
+# their copyright.
+COPYRIGHT_HOLDER = The gPhoto Team
+
+# This is the email address or URL to which the translators shall report
+# bugs in the untranslated strings:
+# - Strings which are not entire sentences, see the maintainer guidelines
+#   in the GNU gettext documentation, section 'Preparing Strings'.
+# - Strings which use unclear terms or require additional context to be
+#   understood.
+# - Strings which make invalid assumptions about notation of date, time or
+#   money.
+# - Pluralisation problems.
+# - Incorrect English spelling.
+# - Incorrect formatting.
+# It can be your email address, or a mailing list address where translators
+# can write to without being subscribed, or the URL of a web page through
+# which the translators can contact you.
+MSGID_BUGS_ADDRESS = $(PACKAGE_BUGREPORT)
+
+# This is the list of locale categories, beyond LC_MESSAGES, for which the
+# message catalogs shall be used.  It is usually empty.
+EXTRA_LOCALE_CATEGORIES =
+
+# This tells whether the $(DOMAIN).pot file contains messages with an 'msgctxt'
+# context.  Possible values are "yes" and "no".  Set this to yes if the
+# package uses functions taking also a message context, like pgettext(), or
+# if in $(XGETTEXT_OPTIONS) you define keywords with a context argument.
+USE_MSGCTXT = no
+
+# These options get passed to msgmerge.
+# Useful options are in particular:
+#   --previous            to keep previous msgids of translated messages,
+#   --quiet               to reduce the verbosity.
+MSGMERGE_OPTIONS =