maint: update to latest gnulib

Several portability changes, but the one we are most interested in
is the improvement to bootstrap to detect perl modules.

This patch doesn't actually change our bootstrap requirements
(that will be a separate patch), but sets the stage for it.

* .gnulib: Update to latest.
* bootstrap: Regenerate from upstream.

Signed-off-by: Eric Blake <eblake@redhat.com>

.gnulib

@@ -1 +1 @@
-Subproject commit 9565c3be73eb6d76b7b42a21d68d2e00a62abb6d
+Subproject commit 3914f3153576e9a5ba4002bde27de05211b5a79c

bootstrap

@@ -1,6 +1,6 @@
 #! /bin/sh
 # Print a version string.
-scriptversion=2013-12-05.23; # UTC
+scriptversion=2014-12-08.12; # UTC
 
 # Bootstrap this package from checked-out sources.
 
@@ -42,6 +42,9 @@ export LC_ALL
 
 local_gl_dir=gl
 
+# Honour $PERL, but work even if there is none
+PERL="${PERL-perl}"
+
 me=$0
 
 usage() {
@@ -210,7 +213,17 @@ bootstrap_sync=false
 use_git=true
 
 check_exists() {
-  ($1 --version </dev/null) >/dev/null 2>&1
+  if test "$1" = "--verbose"; then
+    ($2 --version </dev/null) >/dev/null 2>&1
+    if test $? -ge 126; then
+      # If not found, run with diagnostics as one may be
+      # presented with env variables to set to find the right version
+      ($2 --version </dev/null)
+    fi
+  else
+    ($1 --version </dev/null) >/dev/null 2>&1
+  fi
+
   test $? -lt 126
 }
 
@@ -408,7 +421,7 @@ sort_ver() { # sort -V is not generally available
 get_version() {
   app=$1
 
-  $app --version >/dev/null 2>&1 || return 1
+  $app --version >/dev/null 2>&1 || { $app --version; return 1; }
 
   $app --version 2>&1 |
   sed -n '# Move version to start of line.
@@ -446,6 +459,7 @@ check_versions() {
     test "$appvar" = TAR && appvar=AMTAR
     case $appvar in
         GZIP) ;; # Do not use $GZIP:  it contains gzip options.
+        PERL::*) ;; # Keep perl modules as-is
         *) eval "app=\${$appvar-$app}" ;;
     esac
 
@@ -463,11 +477,22 @@ check_versions() {
           ret=1
           continue
         } ;;
+      # Another check is for perl modules.  These can be written as
+      # e.g. perl::XML::XPath in case of XML::XPath module, etc.
+      perl::*)
+        # Extract module name
+        app="${app#perl::}"
+        if ! $PERL -m"$app" -e 'exit 0' >/dev/null 2>&1; then
+          warn_ "Error: perl module '$app' not found"
+          ret=1
+        fi
+        continue
+        ;;
     esac
     if [ "$req_ver" = "-" ]; then
       # Merely require app to exist; not all prereq apps are well-behaved
       # so we have to rely on $? rather than get_version.
-      if ! check_exists $app; then
+      if ! check_exists --verbose $app; then
         warn_ "Error: '$app' not found"
         ret=1
       fi
@@ -598,8 +623,8 @@ case ${GNULIB_SRCDIR--} in
   # Note that $use_git is necessarily true in this case.
   if git_modules_config submodule.gnulib.url >/dev/null; then
     echo "$0: getting gnulib files..."
-    git submodule init || exit $?
-    git submodule update || exit $?
+    git submodule init -- "$gnulib_path" || exit $?
+    git submodule update -- "$gnulib_path" || exit $?
 
   elif [ ! -d "$gnulib_path" ]; then
     echo "$0: getting gnulib files..."
@@ -628,13 +653,14 @@ case ${GNULIB_SRCDIR--} in
       # This fallback allows at least git 1.5.5.
       if test -f "$gnulib_path"/gnulib-tool; then
         # Since file already exists, assume submodule init already complete.
-        git submodule update || exit $?
+        git submodule update -- "$gnulib_path" || exit $?
       else
         # Older git can't clone into an empty directory.
         rmdir "$gnulib_path" 2>/dev/null
         git clone --reference "$GNULIB_SRCDIR" \
           "$(git_modules_config submodule.gnulib.url)" "$gnulib_path" \
-          && git submodule init && git submodule update \
+          && git submodule init -- "$gnulib_path" \
+          && git submodule update -- "$gnulib_path" \
           || exit $?
       fi
     fi