Inverse-only matches should not reorder the remaining results

Fix #1458

src/core.go

@@ -149,6 +149,7 @@ func Run(opts *Options, revision string) {
 		}
 
 		pattern := patternBuilder([]rune(*opts.Filter))
+		matcher.sort = pattern.sortable
 
 		found := false
 		if streamingFilter {

src/matcher.go

@@ -230,5 +230,5 @@ func (m *Matcher) Reset(chunks []*Chunk, patternRunes []rune, cancel bool, final
 	} else {
 		event = reqRetry
 	}
-	m.reqBox.Set(event, MatchRequest{chunks, pattern, final, sort})
+	m.reqBox.Set(event, MatchRequest{chunks, pattern, final, sort && pattern.sortable})
 }

src/pattern.go

@@ -52,6 +52,7 @@ type Pattern struct {
 	forward       bool
 	text          []rune
 	termSets      []termSet
+	sortable      bool
 	cacheable     bool
 	cacheKey      string
 	delimiter     Delimiter
@@ -101,18 +102,27 @@ func BuildPattern(fuzzy bool, fuzzyAlgo algo.Algo, extended bool, caseMode Case,
 	}
 
 	caseSensitive := true
+	sortable := true
 	termSets := []termSet{}
 
 	if extended {
 		termSets = parseTerms(fuzzy, caseMode, normalize, asString)
+		// We should not sort the result if there are only inverse search terms
+		sortable = false
 	Loop:
 		for _, termSet := range termSets {
 			for idx, term := range termSet {
+				if !term.inv {
+					sortable = true
+				}
 				// If the query contains inverse search terms or OR operators,
 				// we cannot cache the search scope
 				if !cacheable || idx > 0 || term.inv || fuzzy && term.typ != termFuzzy || !fuzzy && term.typ != termExact {
 					cacheable = false
-					break Loop
+					if sortable {
+						// Can't break until we see at least one non-inverse term
+						break Loop
+					}
 				}
 			}
 		}
@@ -134,6 +144,7 @@ func BuildPattern(fuzzy bool, fuzzyAlgo algo.Algo, extended bool, caseMode Case,
 		forward:       forward,
 		text:          []rune(asString),
 		termSets:      termSets,
+		sortable:      sortable,
 		cacheable:     cacheable,
 		nth:           nth,
 		delimiter:     delimiter,

test/test_go.rb

@@ -1519,6 +1519,19 @@ class TestGoFZF < TestBase
     assert_equal ['foo bar'], `#{FZF} -f'^foo\\ bar$' < #{tempname}`.lines.map(&:chomp)
     assert_equal input.lines.count - 1, `#{FZF} -f'!^foo\\ bar$' < #{tempname}`.lines.count
   end
+
+  def test_inverse_only_search_should_not_sort_the_result
+    # Filter
+    assert_equal(%w[aaaaa b ccc],
+      `printf '%s\n' aaaaa b ccc BAD | #{FZF} -f '!bad'`.lines.map(&:chomp))
+
+    # Interactive
+    tmux.send_keys(%[printf '%s\n' aaaaa b ccc BAD | #{FZF} -q '!bad'], :Enter)
+    tmux.until { |lines| lines.item_count == 4 && lines.match_count == 3 }
+    tmux.until { |lines| lines[-3] == '> aaaaa' }
+    tmux.until { |lines| lines[-4] == '  b' }
+    tmux.until { |lines| lines[-5] == '  ccc' }
+  end
 end
 
 module TestShell