[fish] Enable multiple history commands insertion (#4280)

Enable inserting multiple history commands. To disable, set `--no-multi`
through `$FZF_CTRL_R_OPTS`.

Also, remove the usage of `become` action, to avoid leaving behind
temporary files.

Co-authored-by: Junegunn Choi <junegunn.c@gmail.com>

shell/key-bindings.fish

@@ -116,10 +116,9 @@ function fzf_key_bindings
     set -l fzf_query (commandline | string escape)
 
     set -lx FZF_DEFAULT_OPTS (__fzf_defaults '' \
-      '--nth=2..,.. --scheme=history --bind=ctrl-r:toggle-sort --wrap-sign="\t↳ "' \
+      '--nth=2..,.. --scheme=history --multi --wrap-sign="\t↳ "' \
-      "--highlight-line --no-multi $FZF_CTRL_R_OPTS --read0 --print0" \
+      "--bind=ctrl-r:toggle-sort --highlight-line $FZF_CTRL_R_OPTS" \
-      "--bind='enter:become:string replace -a -- \n\t \n {2..} | string collect'" \
+      '--accept-nth=2.. --read0 --print0 --with-shell='(status fish-path)\\ -c)
-      '--with-shell='(status fish-path)\\ -c)
 
     set -lx FZF_DEFAULT_OPTS_FILE
     set -lx FZF_DEFAULT_COMMAND
@@ -138,8 +137,12 @@ function fzf_key_bindings
     # Merge history from other sessions before searching
     test -z "$fish_private_mode"; and builtin history merge
 
-    set -l result (eval $FZF_DEFAULT_COMMAND \| (__fzfcmd) --query=$fzf_query)
+    if set -l result (eval $FZF_DEFAULT_COMMAND \| (__fzfcmd) --query=$fzf_query | string split0)
-    and commandline -- $result
+      commandline -- (string replace -a -- \n\t \n $result[1])
+      test (count $result) -gt 1; and for i in $result[2..-1]
+        commandline -i -- (string replace -a -- \n\t \n \n$i)
+      end
+    end
 
     commandline -f repaint
   end

test/test_shell_integration.rb

@@ -482,4 +482,36 @@ class TestFish < TestBase
     tmux.send_keys "set -g #{name} '#{val}'", :Enter
     tmux.prepare
   end
+
+  def test_ctrl_r_multi
+    tmux.send_keys ':', :Enter
+    tmux.send_keys 'echo "foo', :Enter, 'bar"', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo "bar', :Enter, 'foo"', :Enter
+    tmux.prepare
+    tmux.send_keys 'C-l', 'C-r'
+    block = <<~BLOCK
+      echo "foo
+      bar"
+      echo "bar
+      foo"
+    BLOCK
+    tmux.until do |lines|
+      block.lines.each_with_index do |line, idx|
+        assert_includes lines[-6 + idx], line.chomp
+      end
+    end
+    tmux.send_keys :BTab, :BTab
+    tmux.until { |lines| assert_includes lines[-2], '(2)' }
+    tmux.send_keys :Enter
+    block = <<~BLOCK
+      echo "bar
+      foo"
+      echo "foo
+      bar"
+    BLOCK
+    tmux.until do |lines|
+      assert_equal block.lines.map(&:chomp), lines
+    end
+  end
 end