Ticket #4619: (autogen.sh) - improve creation of POTFILES.in

- current POTFILES.in file detection can output wrong filename
     xgettext output
     #: src/background.c:221 src/filemanager/file.c:858 src/filemanager/file.c:952
     result in
     src/background.csrc/filemanager/file.csrc/filemanager/file.c
- simplify POTFILES.in file detection by using grep only
- find command search files only
- find/grep option should be Solaris OS friendly
- move POTFILES.in creating to configure.ac (more BUILD friendly and future autogen.sh get rid possibility)
- autoconf AC_CONFIG_COMMANDS_POST support since <2.64
- comparing current vs simplify grep file detection result in additional files:
    lib/search/regex.c
    lib/widget/history.c
    lib/widget/quick.h
    src/diffviewer/internal.h
    src/diffviewer/search.c
    src/editor/editdraw.c
    src/editor/etags.c
    src/filemanager/command.c
    src/vfs/tar/tar.c
    src/viewer/lib.c
    tests/src/execute__common.c
    tests/src/execute__execute_with_vfs_arg.c

Signed-off-by: Andreas Mohr <and@gmx.li>
Signed-off-by: Yury V. Zaytsev <yury@shurup.com>

autogen.sh

@@ -13,17 +13,6 @@ ${AUTORECONF:-autoreconf} --verbose --install --force -I m4 ${AUTORECONF_FLAGS}
 # Customize the INSTALL file
 rm -f INSTALL && ln -s doc/INSTALL .
 
-# Generate po/POTFILES.in
-if ! xgettext -h 2>&1 | grep -- '--keyword' >/dev/null ; then
-  echo "gettext is unable to extract translations, set XGETTEXT to GNU gettext!" >&2
-  touch po/POTFILES.in
-else
-  ${XGETTEXT:-xgettext} --keyword=_ --keyword=N_ --keyword=Q_ --output=- \
-	`find . -name '*.[ch]'` | ${SED-sed} -ne '/^#:/{s/#://;s/:[0-9]*/\
-/g;s/ //g;p;}' | \
-	grep -v '^$' | sort | uniq >po/POTFILES.in
-fi
-
 "$srcdir/version.sh" "$srcdir"
 
 if test -x "$srcdir/configure.mc"; then

configure.ac

@@ -733,6 +733,10 @@ tests/src/vfs/extfs/helpers-list/misc/Makefile
 tests/src/vfs/ftpfs/Makefile
 ])
 
+AC_CONFIG_COMMANDS_POST([
+"${srcdir}"/po/create-potfiles_in.sh "${srcdir}"
+])
+
 AC_OUTPUT
 
 AC_MSG_NOTICE([

po/create-potfiles_in.sh

@@ -0,0 +1,12 @@
+#!/bin/sh
+set -e
+
+if [ -z "$1" ] ;then
+    echo "usage: $0 <toplevel-source-dir>"
+    exit 1
+fi
+
+cd "$1" && \
+    "${FIND:-find}" . -type f -name '*.[ch]' -exec \
+    "${GREP:-grep}" -l '_\s*(\s*"' {} + | \
+    "${SORT:-sort}" | "${UNIQ:-uniq}" > po/POTFILES.in