Accept "cd dir/" again instead of using a subdirectory

Commit 69053d962 (Use menu behavior when completing change-directory,
2022-07-19) made ":cd dir/" actually run ":cd dir/first-subdir",
which can be surprising.
This is usually irrelevant because you rarely type the trailing slash.
However it does happen after correcting an error with `<backspace>`
and friends. For for example,

	:cd d<tab>/f<backspace>

results in

	:cd dir/

We should probably fix user expectations here. Do this by adding "dir/"
as valid completion.  This requires us to allow empty candidates in
"RankedMatch" but there's no harm in that. This means we need to
filter out empty completions from shell-script-candidates elsewhere.

Alternative fix: we could revert 69053d962. This would remove the
convenient menu behavior but that wouldn't be a huge deal.

Fixes #4775

1 files changed, 2 insertions, 1 deletions

diff --git a/src/ranked_match.hh b/src/ranked_match.hh
index 379b855d..ec7fe626 100644
--- a/src/ranked_match.hh
+++ b/src/ranked_match.hh
@@ -27,7 +27,7 @@ struct RankedMatch
     bool operator<(const RankedMatch& other) const;
     bool operator==(const RankedMatch& other) const { return m_candidate == other.m_candidate; }
 
-    explicit operator bool() const { return not m_candidate.empty(); }
+    explicit operator bool() const { return m_matches; }
 
 private:
     template<typename TestFunc>
@@ -48,6 +48,7 @@ private:
     friend constexpr bool with_bit_ops(Meta::Type<Flags>) { return true; }
 
     StringView m_candidate{};
+    bool m_matches = false;
     Flags m_flags = Flags::None;
     int m_word_boundary_match_count = 0;
     int m_max_index = 0;