Be more paranoid about quoting in pg_upgrade's test script.

Double-quote $PGDATA in "find" commands introduced by commit da9b580,
in case that path contains spaces or other special characters.

Adjust a few other places so that quoting is done more consistently.
None of the others are actual bugs AFAICS, but it's confusing to readers
if the same thing is done differently in different places.

Noted by Tels.

Discussion: https://postgr.es/m/c96303c04c360bbedaa04f90f515745b.squirrel@sm.webmail.pair.com

Author: tglsfdc

src/bin/pg_upgrade/test.sh

@@ -65,7 +65,7 @@ case $testhost in
 		;;
 esac
 
-POSTMASTER_OPTS="-F -c listen_addresses=$LISTEN_ADDRESSES -k \"$PGHOST\""
+POSTMASTER_OPTS="-F -c listen_addresses=\"$LISTEN_ADDRESSES\" -k \"$PGHOST\""
 export PGHOST
 
 # don't rely on $PWD here, as old shells don't set it
@@ -107,8 +107,8 @@ newsrc=`cd ../../.. && pwd`
 PATH=$bindir:$PATH
 export PATH
 
-BASE_PGDATA=$temp_root/data
-PGDATA="$BASE_PGDATA.old"
+BASE_PGDATA="$temp_root/data"
+PGDATA="${BASE_PGDATA}.old"
 export PGDATA
 rm -rf "$BASE_PGDATA" "$PGDATA"
 
@@ -224,25 +224,25 @@ if [ -n "$pg_dumpall1_status" ]; then
 	exit 1
 fi
 
-PGDATA=$BASE_PGDATA
+PGDATA="$BASE_PGDATA"
 
 standard_initdb 'initdb'
 
-pg_upgrade $PG_UPGRADE_OPTS -d "${PGDATA}.old" -D "${PGDATA}" -b "$oldbindir" -B "$bindir" -p "$PGPORT" -P "$PGPORT"
+pg_upgrade $PG_UPGRADE_OPTS -d "${PGDATA}.old" -D "$PGDATA" -b "$oldbindir" -B "$bindir" -p "$PGPORT" -P "$PGPORT"
 
 # make sure all directories and files have group permissions, on Unix hosts
 # Windows hosts don't support Unix-y permissions.
 case $testhost in
 	MINGW*) ;;
-	*)	if [ `find ${PGDATA} -type f ! -perm 640 | wc -l` -ne 0 ]; then
+	*)	if [ `find "$PGDATA" -type f ! -perm 640 | wc -l` -ne 0 ]; then
 			echo "files in PGDATA with permission != 640";
 			exit 1;
 		fi ;;
 esac
 
 case $testhost in
 	MINGW*) ;;
-	*)	if [ `find ${PGDATA} -type d ! -perm 750 | wc -l` -ne 0 ]; then
+	*)	if [ `find "$PGDATA" -type d ! -perm 750 | wc -l` -ne 0 ]; then
 			echo "directories in PGDATA with permission != 750";
 			exit 1;
 		fi ;;