Fix some shellcheck linter warnings

* admin/diff-tar-files:
* admin/merge-gnulib:
* admin/merge-pkg-config:
* admin/update-copyright:
* build-aux/git-hooks/prepare-commit-msg:
* make-dist: Fix some shellcheck linter warnings.

admin/diff-tar-files

@@ -35,7 +35,7 @@ old_tmp=/tmp/old.$$
 new_tmp=/tmp/new.$$
 trap "rm -f $old_tmp $new_tmp; exit 1" 1 2 15
 
-tar tzf $old_tar | sed -e 's,^[^/]*,,' | sort > $old_tmp
-tar tzf $new_tar | sed -e 's,^[^/]*,,' | sort > $new_tmp
+tar tzf "$old_tar" | sed -e 's,^[^/]*,,' | sort > $old_tmp
+tar tzf "$new_tar" | sed -e 's,^[^/]*,,' | sort > $new_tmp
 diff -u $old_tmp $new_tmp
 rm -f $new_tmp $old_tmp

admin/merge-gnulib

@@ -105,8 +105,8 @@ for module in $AVOIDED_MODULES; do
   avoided_flags="$avoided_flags --avoid=$module"
 done
 
-"$gnulib_srcdir"/gnulib-tool --dir="$src" $GNULIB_TOOL_FLAGS \
-	$avoided_flags $GNULIB_MODULES &&
+"$gnulib_srcdir"/gnulib-tool --dir="$src" "$GNULIB_TOOL_FLAGS" \
+        "$avoided_flags" "$GNULIB_MODULES" &&
 rm -- "$src"lib/gl_openssl.h "$src"m4/fcntl-o.m4 \
       "$src"m4/gl-openssl.m4 \
       "$src"m4/gnulib-cache.m4 "$src"m4/gnulib-tool.m4 \

admin/merge-pkg-config

@@ -60,4 +60,4 @@ test -d m4 || {
 
 printf >&2 '%s\n' "$0: copying $dir/pkg.m4 to m4/pkg.m4"
 
-cp $dir/pkg.m4 m4
+cp "$dir"/pkg.m4 m4

admin/update-copyright

@@ -53,7 +53,7 @@ repo_files=$(git ls-files) &&
 # . They are GMP files, maintained by the GMP project, with their own dates.
 # . Their format cannot withstand changing the contents of copyright strings.
 
-updatable_files=$(find $repo_files \
+updatable_files=$(find "$repo_files" \
   ! -name COPYING \
   ! -name doclicense.texi \
   ! -name gpl.texi \
@@ -74,4 +74,4 @@ updatable_files=$(find $repo_files \
   ! -name 'mini-gmp.[ch]' \
   -print) &&
 
-build-aux/update-copyright $updatable_files
+build-aux/update-copyright "$updatable_files"

build-aux/git-hooks/prepare-commit-msg

@@ -24,9 +24,9 @@ SHA1=$3
 
 # Prefer gawk if available, as it handles NUL bytes properly.
 if type gawk >/dev/null 2>&1; then
-  awk=gawk
+  awk="gawk"
 else
-  awk=awk
+  awk="awk"
 fi
 
 exec $awk '

make-dist

@@ -190,7 +190,7 @@ if [ ! "${version}" ]; then
   exit 1
 fi
 
-echo Version number is $version
+echo Version number is "$version"
 
 if [ $update = yes ]; then
   if ! grep -q "tree holds version  *${version}" README; then
@@ -257,8 +257,8 @@ if [ $check = yes ]; then
   bogosities=
   while read elc; do
       el=`echo $elc | sed 's/c$//'`
-      [ -r $el ] || continue
-      [ $elc -nt $el ] || bogosities="$bogosities $elc"
+      [ -r "$el" ] || continue
+      [ "$elc" -nt "$el" ] || bogosities="$bogosities $elc"
   done < $temp_elc
 
   if [ x"${bogosities}" != x"" ]; then
@@ -271,7 +271,7 @@ if [ $check = yes ]; then
 
   bogosities=
   for file in $losers; do
-    grep -q "^;.*no-byte-compile: t" $file && continue
+    grep -q "^;.*no-byte-compile: t" "$file" && continue
     case $file in
       site-init.el | site-load.el | site-start.el | default.el) continue ;;
     esac
@@ -295,8 +295,8 @@ if [ $check = yes ]; then
       info=`sed -n 's/^@setfilename //p' $texi | sed 's|.*info/||'`
       [ x"${info}" != x"" ] || continue
       info=info/$info
-      [ -r $info ] || continue
-      [ $info -nt $texi ] || bogosities="$bogosities $info"
+      [ -r "$info" ] || continue
+      [ "$info" -nt "$texi" ] || bogosities="$bogosities $info"
   done < $temp_el
 
   rm -f $temp_el
@@ -407,7 +407,7 @@ if ( [ $update = yes ] || [ ! -f $manifest ] ) && [ -r .git ]; then
   else
     git ls-files | grep -v '^test' >$manifest
   fi || exit
-  printf '%s\n' $possibly_non_vc_files $info_files >>$manifest || exit
+  printf '%s\n' "$possibly_non_vc_files" "$info_files" >>$manifest || exit
   sort -u -o $manifest $manifest || exit
 fi
 
@@ -424,7 +424,7 @@ if [ $verbose = yes ] && (mkdir --verbose ${tempdir}) >/dev/null 2>&1; then
   mkdir_verbose='mkdir --verbose'
 else
   mkdir $tempdir || exit
-  mkdir_verbose=mkdir
+  mkdir_verbose="mkdir"
 fi
 
 # file_to_skip is normally empty to link every file,
@@ -460,14 +460,14 @@ MANIFEST_subdir_sed='
   s,^,'$tempdir'/,
 '
 tempsubdirs=$(sed "$MANIFEST_subdir_sed" $manifest | sort -u)
-$mkdir_verbose -p $tempsubdirs || exit
+$mkdir_verbose -p "$tempsubdirs" || exit
 
 echo "Making links to files"
 while read file; do
   case $file in
     MANIFEST) ln $manifest $tempdir/MANIFEST || exit ;;
     $file_to_skip) continue ;;
-    *) ln $file $tempdir/$file || exit ;;
+    *) ln "$file" $tempdir/"$file" || exit ;;
   esac
 done <$manifest
 
@@ -476,7 +476,7 @@ if [ "${newer}" ]; then
   ## We remove .elc files unconditionally, on the theory that anyone picking
   ## up an incremental distribution already has a running Emacs to byte-compile
   ## them with.
-  find ${tempdir} \( -name '*.elc' -o ! -newer ${newer} \) \
+  find ${tempdir} \( -name '*.elc' -o ! -newer "${newer}" \) \
     -exec rm -f {} \; || exit
 fi
 
@@ -487,12 +487,12 @@ if [ "${make_tar}" = yes ]; then
     sed -e 's/^:/.:/' -e 's/::/:.:/g' -e 's/:$/:./' -e 's/:/ /g'
   `
   for dir in ${temppath}; do
-    [ -x ${dir}/$default_gzip ] || continue
+    [ -x "${dir}"/$default_gzip ] || continue
     found=1; break
   done
   if [ "$found" = "0" ]; then
     echo "WARNING: '$default_gzip' not found, will not compress" >&2
-    default_gzip=cat
+    default_gzip="cat"
   fi
   case "${default_gzip}" in
     bzip2) gzip_extension=.bz2 ;;
@@ -508,17 +508,17 @@ if [ "${make_tar}" = yes ]; then
 
   (cd $tempparent &&
    case $default_gzip in
-     cat) tar $taropt -cf - $emacsname;;
-     *) if tar $taropt -cf /dev/null --use-compress-program="$default_gzip" \
+     cat) tar "$taropt" -cf - $emacsname;;
+     *) if tar "$taropt" -cf /dev/null --use-compress-program="$default_gzip" \
 	       $emacsname/src/lisp.h > /dev/null 2>&1
 	then
-	  tar $taropt -cf - --use-compress-program="$default_gzip" $emacsname
+          tar "$taropt" -cf - --use-compress-program="$default_gzip" $emacsname
 	else
-	  tar $taropt -cf $emacsname.tar $emacsname &&
+          tar "$taropt" -cf $emacsname.tar $emacsname &&
 	  $default_gzip <$emacsname.tar
         fi;;
    esac
-  ) >$emacsname.tar$gzip_extension || exit
+  ) >$emacsname.tar"$gzip_extension" || exit
 fi
 
 ## Why are we deleting the staging directory if clean_up is no?