fish_add_path: Handle moving multiple arguments correctly

This `set -e` had a cartesian product that caused it to remove the
indexes separately, so the later indexes were off - removing the first
and then the second ends up removing the first and then the
old-*third* which is now the second.

Just quote the expansion so it runs in one go.

Fixes #7776

share/functions/fish_add_path.fish

@@ -63,7 +63,7 @@ function fish_add_path --description "Add paths to the PATH"
     set -l newvar $$var
     if set -q _flag_move; and set -q indexes[1]
         # We remove in one step, so the indexes don't move.
-        set -e newvar[$indexes]
+        set -e newvar["$indexes"]
     end
     set $mode newvar $newpaths
 

tests/checks/fish_add_path.fish

@@ -54,4 +54,8 @@ fish_add_path -nP $tmpdir/etc | string replace -- $tmpdir ''
 test "$oldpath" = "$PATH"
 or echo "PATH CHANGED!!!" >&2
 
+# See that moving multiple arguments removes the correct ones - #7776
+PATH=$tmpdir/{bin,etc,link,sbin} fish_add_path -nPpm $tmpdir/{link,sbin} | string replace -a $tmpdir ''
+# CHECK: set PATH /link /sbin /bin /etc
+
 exit 0