fish: Fixes and improvements to CTRL-R (#4703)

Fixes:
- Commands with trailing newlines
- Very long previews

Improvements:
- SHIFT-DELETE performance
- Bind ALT-T: cycle command prefix (timestamp, date/time, none)
- Set comment color for prefix

shell/key-bindings.fish

@@ -183,36 +183,26 @@ function fzf_key_bindings
     set -l -- fzf_query (string escape -- $command_line[$current_line])
 
     set -lx -- FZF_DEFAULT_OPTS (__fzf_defaults '' \
-      '--nth=2..,.. --scheme=history --multi --no-multi-line --no-wrap --wrap-sign="\t\t\t↳ " --preview-wrap-sign="↳ "' \
-      '--bind=\'shift-delete:execute-silent(for i in (string split0 -- <{+f}); eval builtin history delete --exact --case-sensitive -- (string escape -n -- $i | string replace -r "^\d*\\\\\\t" ""); end)+reload(eval $FZF_DEFAULT_COMMAND)\'' \
-      '--bind="alt-enter:become(string join0 -- (string collect -- {+2..} | fish_indent -i))"' \
+      '--with-nth=2.. --nth=2..,.. --scheme=history --multi --no-multi-line' \
+      '--no-wrap --wrap-sign="\t\t\t↳ " --preview-wrap-sign="↳ " --freeze-left=1' \
+      '--bind="alt-enter:become(set -g fzf_temp {+sf3..}; string join0 -- (string split0 -- <$fzf_temp | fish_indent -i); unlink $fzf_temp &>/dev/null)"' \
+      '--bind="alt-t:change-with-nth(1,3..|3..|2..)"' \
+      '--bind="shift-delete:execute-silent(eval builtin history delete -Ce -- (string escape -n -- (string split0 -- <{+sf3..})))+reload(eval $FZF_DEFAULT_COMMAND)"' \
       "--bind=ctrl-r:toggle-sort,alt-r:toggle-raw --highlight-line $FZF_CTRL_R_OPTS" \
-      '--accept-nth=2.. --delimiter="\t" --tabstop=4 --read0 --print0 --with-shell='(status fish-path)\\ -c)
+      '--accept-nth=3.. --delimiter="\t" --tabstop=4 --read0 --print0 --with-shell='(status fish-path)\\ -c)
 
     # Add dynamic preview options if preview command isn't already set by user
     if string match -qvr -- '--preview[= ]' "$FZF_DEFAULT_OPTS"
-      # Convert the highlighted timestamp using the date command if available
-      set -l -- date_cmd '{1}'
-      if type -q date
-        if date -d @0 '+%s' 2>/dev/null | string match -q 0
-          # GNU date
-          set -- date_cmd '(date -d @{1} \\"+%F %a %T\\")'
-        else if date -r 0 '+%s' 2>/dev/null | string match -q 0
-          # BSD date
-          set -- date_cmd '(date -r {1} \\"+%F %a %T\\")'
-        end
-      end
-
-      # Prepend the options to allow user customizations
+      # Prepend the options to allow user overrides
       set -p -- FZF_DEFAULT_OPTS \
-        '--bind="focus,resize:bg-transform:if test \\"$FZF_COLUMNS\\" -gt 100 -a \\\\( \\"$FZF_SELECT_COUNT\\" -gt 0 -o \\\\( -z \\"$FZF_WRAP\\" -a (string length -- {}) -gt (math $FZF_COLUMNS - 4) \\\\) -o (string collect -- {2..} | fish_indent | count) -gt 1 \\\\); echo show-preview; else echo hide-preview; end"' \
-        '--preview="string collect -- (test \\"$FZF_SELECT_COUNT\\" -gt 0; and string collect -- {+2..}) \\"\\n# \\"'$date_cmd' {2..} | fish_indent --ansi"' \
+        '--bind="focus,multi,resize:bg-transform:if test \\"$FZF_COLUMNS\\" -gt 100 -a \\\\( \\"$FZF_SELECT_COUNT\\" -gt 0 -o \\\\( -z \\"$FZF_WRAP\\" -a (string join0 -- <{f3..} | string length) -gt (math $FZF_COLUMNS - (switch $FZF_WITH_NTH; case 2..; echo 13; case 1,3..; echo 25; case 3..; echo 1; end)) \\\\) -o (string split0 -- <{sf3..} | fish_indent | count) -gt 1 \\\\); echo show-preview; else echo hide-preview; end"' \
+        '--preview="test \\"$FZF_SELECT_COUNT\\" -gt 0; and string split0 -- <{+sf3..} | fish_indent --only-indent --ansi; and echo -n \\\\n; string collect -- \\\\#\\\\ {1} (string split0 -- <{sf3..}) | fish_indent --ansi"' \
         '--preview-window="right,50%,wrap-word,follow,info,hidden"'
     end
 
     set -lx FZF_DEFAULT_OPTS_FILE
 
-    set -lx -- FZF_DEFAULT_COMMAND 'builtin history -z --show-time="%s%t"'
+    set -lx -- FZF_DEFAULT_COMMAND 'builtin history -z'
 
     # Enable syntax highlighting colors on fish v4.3.3 and newer
     if set -l -- v (string match -r -- '^(\d+)\.(\d+)(?:\.(\d+))?' $version)
@@ -221,7 +211,9 @@ function fzf_key_bindings
       \( -n "$v[4]" -a "$v[4]" -ge 3 \) \)
 
       set -a -- FZF_DEFAULT_OPTS '--ansi'
-      set -a -- FZF_DEFAULT_COMMAND '--color=always'
+      set -a -- FZF_DEFAULT_COMMAND '--color=always --show-time=(set_color $fish_color_comment)"%F %a %T%t%s%t"(set_color $fish_color_normal)'
+    else
+      set -a -- FZF_DEFAULT_COMMAND '--show-time="%F %a %T%t%s%t"'
     end
 
     # Merge history from other sessions before searching