Fix escaping of meta characters after ' or ! prefix

https://github.com/junegunn/fzf/issues/444#issuecomment-321432803

src/pattern.go

@@ -182,7 +182,9 @@ func parseTerms(fuzzy bool, caseMode Case, normalize bool, str string) []termSet
 			}
 		}
 
-		if strings.HasPrefix(text, "'") {
+		if _escapedPrefixRegex.MatchString(text) {
+			text = text[1:]
+		} else if strings.HasPrefix(text, "'") {
 			// Flip exactness
 			if fuzzy && !inv {
 				typ = termExact
@@ -200,10 +202,6 @@ func parseTerms(fuzzy bool, caseMode Case, normalize bool, str string) []termSet
 			text = text[1:]
 		}
 
-		if _escapedPrefixRegex.MatchString(text) {
-			text = text[1:]
-		}
-
 		if len(text) > 0 {
 			if switchSet {
 				sets = append(sets, set)

test/test_go.rb

@@ -1400,6 +1400,16 @@ class TestGoFZF < TestBase
     assert_equal [], `#{FZF} -f"'br" < #{tempname}`.lines.map(&:chomp)
     assert_equal ["foo'bar"], `#{FZF} -f"\\'br" < #{tempname}`.lines.map(&:chomp)
   end
+
+  def test_escaped_meta_characters_only_on_relevant_positions
+    input = <<~EOF
+      \\^
+      ^
+    EOF
+    writelines tempname, input.lines.map(&:chomp)
+    assert_equal %w[^ \\^], `#{FZF} -f"\\^" < #{tempname}`.lines.map(&:chomp)
+    assert_equal %w[\\^], `#{FZF} -f"'\\^" < #{tempname}`.lines.map(&:chomp)
+  end
 end
 
 module TestShell