From 96ebfaaf87ff28a8abbb8661a3911fb75f494366 Mon Sep 17 00:00:00 2001
From: Aaron Gyes <me@aaron.gy>
Date: Sun, 18 Sep 2016 02:08:19 -0700
Subject: [PATCH] Use 'grealpath' if installed for realpath fallback (#3374)

* Use 'grealpath' if installed for realpath fallback

See discussion in #3370

* fish_realpath: filter out dangerous options

Per feedback do not use aliases to declare wrapped functions.
---
 share/functions/realpath.fish | 39 ++++++++++++++++++++++++++++++++---
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/share/functions/realpath.fish b/share/functions/realpath.fish
index 3d33ae0f3..2bcfc5ff5 100644
--- a/share/functions/realpath.fish
+++ b/share/functions/realpath.fish
@@ -6,8 +6,41 @@
 # If we see that there is an external command by that name we just return. That will cause fish to
 # run the external command. On the other hand, if an external command isn't found we define a
 # function that will provide fallback behavior.
-if not type -q -P realpath
-    function realpath --description 'fallback realpath implementation'
-        builtin fish_realpath $argv[-1]
+if not command -s realpath >/dev/null
+
+    if command -s grealpath >/dev/null
+        function realpath -w grealpath -d "print the resolved path [grealpath]"
+            grealpath $argv
+        end
+    else
+        function realpath -w fish_realpath -d "get an absolute path without symlinks [fish_realpath]"
+            if test -z $argv
+                printf "usage: %s%s%s %sfile%s …\n" (set_color -o) $_ (set_color normal) (set_color -u) (set_color normal)
+                echo "       resolves files as absolute paths without symlinks"
+                return 1
+            end
+
+            for arg in $argv
+                switch $arg
+                    # These - no can do our realpath
+                    case -s --strip --no-symlinks -z --zero --relative-base\* --relative-to\*
+                        __fish_print_help fish_realpath
+                        return 2
+
+                    case -h --help --version
+                        __fish_print_help fish_realpath
+                        return 0
+
+                        # Service commands called with these arguments by
+                        # dropping the arguments to protext fish_realpath from them
+                        # There are no sure things here
+                    case -e --canonicalize-existing --physical -P -q --quiet -m --canonicalize-missing
+                        continue
+
+                    case "*"
+                        fish_realpath $argv
+                end
+            end
+        end
     end
 end