xgettext fails to detect plurals

[Urs Janßen]

Tested with xgettext 0.21 and 0.22.5.

To reproduce you need the three attached files.
(can be compiled with
        cc -I. strngs.c main.c -o bug
 could be invoked with one numeric arg, eg.
        ./bug 1
)

Running
        xgettext \
                --keyword=_ --keyword=N_ --keyword=P_:1,2 \
                main.c strngs.c -o bug.pot
doesn't detect that txt_s and txt_p are plural forms of the same
message. Instead of resulting in something like

#: strngs.c:2 strngs.c:3
msgid "single"
msgid_plural "plural"
msgstr[0] ""
msgstr[1] ""

#: strngs.c:4
msgid "something"
msgstr ""

it results in

#: strngs.c:2
msgid "single"
msgstr ""

#: strngs.c:3
msgid "plural"
msgstr ""

#: strngs.c:4
msgid "something"
msgstr ""

Is there any option/way to tell xgettext to "resolve" the indirection?

Thanks,
urs

main.c
Description: Text Data

strngs.c
Description: Text Data

ext.h
Description: Text Data