Update fish

functions/_fzf_preview_changed_file.fish

@@ -0,0 +1,30 @@
+# helper for _fzf_search_git_status
+# arg should be a line from git status --short, e.g.
+# MM functions/_fzf_preview_changed_file.fish
+#  D README.md
+# R  LICENSE.md -> LICENSE
+function _fzf_preview_changed_file --description "Show the untracked, staged, and/or unstaged changes in the given file."
+    set -l path (string split ' ' $argv)[-1]
+    # first letter of short format shows index, second letter shows working tree
+    # https://git-scm.com/docs/git-status/2.35.0#_output
+    set -l index_status (string sub --length 1 $argv)
+    set -l working_tree_status (string sub --start 2 --length 1 $argv)
+
+    if test $index_status = '?'
+        _fzf_report_diff_type Untracked
+        _fzf_preview_file $path
+    else
+        # no-prefix because the file is always being compared to itself so is unecessary
+        set diff_opts --color=always --no-prefix
+
+        if test $index_status != ' '
+            _fzf_report_diff_type Staged
+            git diff --staged $diff_opts -- $path
+        end
+
+        if test $working_tree_status != ' '
+            _fzf_report_diff_type Unstaged
+            git diff $diff_opts -- $path
+        end
+    end
+end