feat(zsh): Handle multi-line history selection (#4595)

Author: LangLangBart

shell/key-bindings.zsh

@@ -128,25 +128,52 @@ fi
 
 # CTRL-R - Paste the selected command from history into the command line
 fzf-history-widget() {
-  local selected
-  setopt localoptions noglobsubst noposixbuiltins pipefail no_aliases noglob nobash_rematch 2> /dev/null
+  local selected extracted_with_perl=0
+  setopt localoptions noglobsubst noposixbuiltins pipefail no_aliases no_glob no_ksharrays extendedglob 2> /dev/null
   # Ensure the module is loaded if not already, and the required features, such
   # as the associative 'history' array, which maps event numbers to full history
   # lines, are set. Also, make sure Perl is installed for multi-line output.
   if zmodload -F zsh/parameter p:{commands,history} 2>/dev/null && (( ${+commands[perl]} )); then
     selected="$(printf '%s\t%s\000' "${(kv)history[@]}" |
       perl -0 -ne 'if (!$seen{(/^\s*[0-9]+\**\t(.*)/s, $1)}++) { s/\n/\n\t/g; print; }' |
-      FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '\t↳ ' --highlight-line ${FZF_CTRL_R_OPTS-} --query=${(qqq)LBUFFER} +m --read0") \
+      FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '\t↳ ' --highlight-line --multi ${FZF_CTRL_R_OPTS-} --query=${(qqq)LBUFFER} --read0") \
       FZF_DEFAULT_OPTS_FILE='' $(__fzfcmd))"
+      extracted_with_perl=1
   else
     selected="$(fc -rl 1 | __fzf_exec_awk '{ cmd=$0; sub(/^[ \t]*[0-9]+\**[ \t]+/, "", cmd); if (!seen[cmd]++) print $0 }' |
-      FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '\t↳ ' --highlight-line ${FZF_CTRL_R_OPTS-} --query=${(qqq)LBUFFER} +m") \
+      FZF_DEFAULT_OPTS=$(__fzf_defaults "" "-n2..,.. --scheme=history --bind=ctrl-r:toggle-sort,alt-r:toggle-raw --wrap-sign '\t↳ ' --highlight-line --multi ${FZF_CTRL_R_OPTS-} --query=${(qqq)LBUFFER}") \
       FZF_DEFAULT_OPTS_FILE='' $(__fzfcmd))"
   fi
   local ret=$?
+  local -a cmds
+  # Avoid leaking auto assigned values when using backreferences '(#b)'
+  local -a mbegin mend match
   if [ -n "$selected" ]; then
-    if [[ $(__fzf_exec_awk '{print $1; exit}' <<< "$selected") =~ ^[1-9][0-9]* ]]; then
-      zle vi-fetch-history -n $MATCH
+    # Heuristic to check if the selected value is from history or a custom query
+    if ((( extracted_with_perl )) && [[ $selected == <->$'\t'* ]]) ||
+    ((( ! extracted_with_perl )) && [[ $selected == [[:blank:]]#<->(  |\* )* ]]); then
+      # Split at newlines
+      for line in ${(ps:\n:)selected}; do
+        if (( extracted_with_perl )); then
+          if [[ $line == (#b)(<->)(#B)$'\t'* ]]; then
+            (( ${+history[${match[1]}]} )) && cmds+=("${history[${match[1]}]}")
+          fi
+        elif [[ $line == [[:blank:]]#(#b)(<->)(#B)(  |\* )* ]]; then
+          # Avoid $history array: lags behind 'fc' on foreign commands (*)
+          # https://zsh.org/mla/users/2024/msg00692.html
+          # Push BUFFER onto stack; fetch and save history entry from BUFFER; restore
+          zle .push-line
+          zle vi-fetch-history -n ${match[1]}
+          (( ${#BUFFER} )) && cmds+=("${BUFFER}")
+          BUFFER=""
+          zle .get-line
+        fi
+      done
+      if (( ${#cmds[@]} )); then
+        # Join by newline after stripping trailing newlines from each command
+        BUFFER="${(pj:\n:)${(@)cmds%%$'\n'#}}"
+        CURSOR=${#BUFFER}
+      fi
     else # selected is a custom query, not from history
       LBUFFER="$selected"
     fi

test/test_shell_integration.rb

@@ -462,6 +462,84 @@ def test_complete_quoted_command
       tmux.send_keys 'C-c'
     end
   end
+
+  # Helper function to run test with Perl and again with Awk
+  def self.test_perl_and_awk(name, &block)
+    define_method("test_#{name}") do
+      instance_eval(&block)
+    end
+
+    define_method("test_#{name}_awk") do
+      tmux.send_keys "unset 'commands[perl]'", :Enter
+      tmux.prepare
+      # Verify perl is actually unset (0 = not found)
+      tmux.send_keys 'echo ${+commands[perl]}', :Enter
+      tmux.until { |lines| assert_equal '0', lines[-1] }
+      tmux.prepare
+      instance_eval(&block)
+    end
+  end
+
+  def prepare_ctrl_r_test
+    tmux.send_keys ':', :Enter
+    tmux.send_keys 'echo match-collision', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo "line 1', :Enter, '2 line 2"', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo "foo', :Enter, 'bar"', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo "bar', :Enter, 'foo"', :Enter
+    tmux.prepare
+    tmux.send_keys 'echo "trailing_space "', :Enter
+    tmux.prepare
+    tmux.send_keys 'cat <<EOF | wc -c', :Enter, 'qux thud', :Enter, 'EOF', :Enter
+    tmux.prepare
+    tmux.send_keys 'C-l', 'C-r'
+  end
+
+  test_perl_and_awk 'ctrl_r_accept_or_print_query' do
+    set_var('FZF_CTRL_R_OPTS', '--bind enter:accept-or-print-query')
+    prepare_ctrl_r_test
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys '1 foobar'
+    tmux.until { |lines| assert_equal 0, lines.match_count }
+    tmux.send_keys :Enter
+    tmux.until { |lines| assert_equal '1 foobar', lines[-1] }
+  end
+
+  test_perl_and_awk 'ctrl_r_multiline_index_collision' do
+    # Leading number in multi-line history content is not confused with index
+    prepare_ctrl_r_test
+    tmux.send_keys "'line 1"
+    tmux.until { |lines| assert_equal 1, lines.match_count }
+    tmux.send_keys :Enter
+    tmux.until do |lines|
+      assert_equal ['echo "line 1', '2 line 2"'], lines[-2..]
+    end
+  end
+
+  test_perl_and_awk 'ctrl_r_multi_selection' do
+    prepare_ctrl_r_test
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys :BTab, :BTab, :BTab
+    tmux.until { |lines| assert_includes lines[-2], '(3)' }
+    tmux.send_keys :Enter
+    tmux.until do |lines|
+      assert_equal ['cat <<EOF | wc -c', 'qux thud', 'EOF', 'echo "trailing_space "', 'echo "bar', 'foo"'], lines[-6..]
+    end
+  end
+
+  test_perl_and_awk 'ctrl_r_no_multi_selection' do
+    set_var('FZF_CTRL_R_OPTS', '--no-multi')
+    prepare_ctrl_r_test
+    tmux.until { |lines| assert_operator lines.match_count, :>, 0 }
+    tmux.send_keys :BTab, :BTab, :BTab
+    tmux.until { |lines| refute_includes lines[-2], '(3)' }
+    tmux.send_keys :Enter
+    tmux.until do |lines|
+      assert_equal ['cat <<EOF | wc -c', 'qux thud', 'EOF'], lines[-3..]
+    end
+  end
 end
 
 class TestFish < TestBase