Fix remote path escaping for rsync and scp completions

They need to be escaped twice, for the local and the remote shell.
Also don't suggest local files as rsync remote paths (-a -> -xa) and
fix completion for remote paths containing multiple consecutive spaces.

Fixes #1872
[ci skip]

share/completions/rsync.fish

@@ -1,5 +1,5 @@
 function __rsync_remote_target
-    commandline -ct | string match -r '.*::?(?:.*/)?'
+    commandline -ct | string match -r '.*::?(?:.*/)?' | string unescape
 end
 
 complete -c rsync -s v -l verbose -d "Increase verbosity"
@@ -125,12 +125,14 @@ complete -c rsync -d Hostname -a "
 #
 # Remote path
 #
-complete -c rsync -d "Remote path" -n "commandline -ct | string match -q '*:*'" -a "
+complete -c rsync -d "Remote path" -n "commandline -ct | string match -q '*:*'" -xa "
 (
 	# Prepend any user@host:/path information supplied before the remote completion.
         __rsync_remote_target
 )(
 	# Get the list of remote files from the specified rsync server.
-        rsync --list-only (__rsync_remote_target) 2>/dev/null | string replace -r '^d.*' '\$0/' | tr -s ' ' | cut -d' ' -f 5-
+        rsync --list-only (__rsync_remote_target) 2>/dev/null | string replace -r '^d.*' '\$0/' |
+        string replace -r '(\S+\s+){4}' '' | # drop the first four columns
+        string escape -n
 )
 "

share/completions/scp.fish

@@ -54,7 +54,8 @@ complete -c scp -d "Local Path" -n "not string match @ -- (commandline -ct)"
 # Get the list of remote files from the scp target.
 complete -c scp -d "Remote Path" -f -n "commandline -ct | string match -e ':'" -a "
 (__scp_remote_target):( \
-        command ssh (__scp2ssh_port_number) -o 'BatchMode yes' (__scp_remote_target) /bin/ls\ -dp\ (__scp_remote_path_prefix)\* 2>/dev/null
+        command ssh (__scp2ssh_port_number) -o 'BatchMode yes' (__scp_remote_target) /bin/ls\ -dp\ (__scp_remote_path_prefix | string unescape)\* 2>/dev/null |
+        string escape -n
 )
 "
 complete -c scp -s B -d "Batch mode"