Fix bugs in new import command as discussed in oh-my-fish/pull/291

+ All `.load` files inside custom are sourced as usual.

+ Only set plugins set in `$fish_plugins` as imported. Works whether they are in `$fish_path` or `$fish_custom` as expected. The same for plugins.

+ `$fish_function_path` is not polluted.

functions/_prepend_tree.fish

@@ -2,17 +2,17 @@
 #      _prepend_tree - add a dependency tree to fish_function_path
 #
 # SYNOPSIS
-#      _prepend_tree [-p --preview] <path> [<glob>..]
+#      _prepend_tree [-v --verbose] <path> [<glob>..]
 #
 # DESCRIPTION
-#      Search a path tree and prepend directories with fish files
-#      printing any matches by default. Use a glob list to include
-#      or exclude other file extensions. Use -p --preview to just
-#      print matches withouth modifying the path.
+#      Search a path tree and prepend directories with fish files. Use a glob
+#      list to include or exclude other file extensions. Use -v --verbose to
+#      output directories to be added to the path.
 #
 # OPTIONS
-#      [-p --preview]
-#          Do not modify the path. Print directories that match the glob.
+#      [-v --verbose]
+#          Optional. Print directories that match the glob. Must be the
+#          first argument if used.
 #
 #      <path>
 #          Required. Specify the path to search for glob patterns.
@@ -46,15 +46,21 @@
 # SEE ALSO
 #      .oh-my-fish/functions/_prepend_path.fish
 #
-# v.0.2.1
+# v.0.2.0
 #/
 function _prepend_tree -d "Add a dependency tree to the Fish path."
   # Match directories with .fish files always.
   set -l glob -name \*.fish
+  set -l verbose ""
+
+  # Retrieve first argument, either the path or the -v option.
   set -l path $argv[1]
-  if contains -- $path -p --preview
+  if contains -- $path -v --verbose
+    set verbose -v
+    # Option first, path should be next.
     set path $argv[2]
   end
+
   # Parse glob options to create the main glob pattern.
   if [ (count $argv) -gt 2 ]
     set -l operator -o
@@ -82,16 +88,22 @@ function _prepend_tree -d "Add a dependency tree to the Fish path."
   # $subs will become an empty list for directories without sub directories
   # which is safe to use in the loop.
   set -l subs $path/**/
-  
+
   # Traverse $path and $subs prepending only directories with matches.
   for dir in $path $subs
-    # Use head to retrieve at least the first match.
-    if [ -z (find $dir $glob -maxdepth 1 | head -1) ]
+    # Use head to retrieve at least one match. Ignore errors for non
+    # existing directories
+    if [ -z (find "$dir" $glob -maxdepth 1 ^/dev/null | head -1) ]
       continue
     end
-    printf "%s" $dir
-    if not contains -- $argv[1] -p --preview
-      _prepend_path $dir -d fish_function_path
+
+    # Print matched directories if the -v option is set.
+    if not [ -z $verbose ]
+      printf "%s\n" $dir
     end
+
+    # Prepend matched directory to the the global fish function path.
+    # Note path duplicates are already handled by _prepend_path.
+    _prepend_path $dir -d fish_function_path
   end
 end

functions/import.fish

@@ -25,19 +25,23 @@
 #      functions/_prepend_path.fish
 #      functions/_prepend_tree.fish
 #
-# v.0.2.1
+# v.0.1.0
 #/
 function import -d "Load libraries, plugins, themes, etc."
   for library in $argv
     # Prepend plugins, themes and completions, traversing library
     # trees and prepending directories with fish code.
-    _prepend_tree $fish_path/$library >/dev/null
+    _prepend_tree $fish_path/$library
+    _prepend_tree $fish_custom/$library
     _prepend_path $fish_path/$library/completions -d fish_complete_path
 
+    # Set path to load files.
+    set -l path $library/(basename $library).load
+
     # Source each plugin, theme, etc., configuration load file.
-    for path in $fish_path/$library/(basename $library).load
-      if [ -e $path ]
-        . $path
+    for load in $fish_path/$path $fish_custom/$path
+      if [ -e $load ]
+        . $load
       end
     end
   end

oh-my-fish.fish

@@ -10,24 +10,21 @@ end
 set user_function_path $fish_function_path[1]
 set -e fish_function_path[1]
 
-# Add functions defined in oh-my-fish/functions to path.
+# Add functions defined in oh-my-fish/functions to the path.
 if not contains $fish_path/functions/ $fish_function_path
   set fish_function_path $fish_path/functions/ $fish_function_path
 end
 
-# Add required plugins, completions and themes. Imported commands can be
-# customized via the $fish_path/custom directory. To customize a theme,
-# create a directory under $fish_path/custom/themes with the same name
-# as the theme. Use the same approach for plugins, etc.
-import plugins/$fish_plugins themes/$fish_theme
+# Add imported plugins, completions and themes. Customize imported
+# commands via the $fish_path/custom directory, for example create
+# a directory under $fish_path/custom/themes with the same name as
+# the theme and override any functions/variables there. Rinse and
+# repeat for plugins.
+import $fish_plugins themes/$fish_theme
 
-# Prepend all user custom paths to the fish path and source load files.
-for custom_file in $fish_custom/**
-  _prepend_path $custom_file -d fish_function_path
-  switch $custom_file
-    case \*.load
-      . $custom_file
-  end
+# Source all files inside custom directory.
+for load in $fish_custom/*.load
+  . $load
 end
 
 # Prepend extracted user functions so they have the highest priority.