From 617342ffb45c529ffb6d41fb12b9960fe031383e Mon Sep 17 00:00:00 2001
From: Riccardo Mazzarini <me@noib3.dev>
Date: Sun, 12 Nov 2023 13:09:41 +0100
Subject: [PATCH] fzf: return a null score if pattern is empty

---
 src/algos/fzf/common.rs | 16 ++++++++++++++++
 src/algos/fzf/v1.rs     |  4 ++++
 src/algos/fzf/v2.rs     |  4 ++++
 tests/fzf_v2.rs         | 13 +++++++++++++
 4 files changed, 37 insertions(+)

diff --git a/src/algos/fzf/common.rs b/src/algos/fzf/common.rs
index 62f0a86..e089374 100644
--- a/src/algos/fzf/common.rs
+++ b/src/algos/fzf/common.rs
@@ -110,6 +110,10 @@ pub(super) fn exact_match(
     with_matched_ranges: bool,
     matched_ranges: &mut MatchedRanges,
 ) -> Option<Score> {
+    if pattern.is_empty() {
+        return Some(0);
+    }
+
     // TODO: docs
     let mut best_bonus: i64 = -1;
 
@@ -209,6 +213,10 @@ pub(super) fn prefix_match(
     with_matched_ranges: bool,
     matched_ranges: &mut MatchedRanges,
 ) -> Option<Score> {
+    if pattern.is_empty() {
+        return Some(0);
+    }
+
     let mut pattern_chars = pattern.chars();
 
     let ignored_leading_spaces =
@@ -256,6 +264,10 @@ pub(super) fn suffix_match(
     with_matched_ranges: bool,
     matched_ranges: &mut MatchedRanges,
 ) -> Option<Score> {
+    if pattern.is_empty() {
+        return Some(0);
+    }
+
     let mut pattern_chars = pattern.chars().rev();
 
     let up_to_ignored_spaces = candidate.len()
@@ -305,6 +317,10 @@ pub(super) fn equal_match(
     with_matched_ranges: bool,
     matched_ranges: &mut MatchedRanges,
 ) -> Option<Score> {
+    if pattern.is_empty() {
+        return Some(0);
+    }
+
     let ignored_leading_spaces =
         ignored_candidate_leading_spaces(pattern, candidate)?;
 
diff --git a/src/algos/fzf/v1.rs b/src/algos/fzf/v1.rs
index 2bd804d..113b22d 100644
--- a/src/algos/fzf/v1.rs
+++ b/src/algos/fzf/v1.rs
@@ -172,6 +172,10 @@ pub(super) fn fzf_v1(
     is_candidate_ascii: bool,
     matched_ranges: &mut MatchedRanges,
 ) -> Option<Score> {
+    if pattern.is_empty() {
+        return Some(0);
+    }
+
     let range_forward = forward_pass(
         pattern,
         candidate,
diff --git a/src/algos/fzf/v2.rs b/src/algos/fzf/v2.rs
index 4346a9d..971bfa6 100644
--- a/src/algos/fzf/v2.rs
+++ b/src/algos/fzf/v2.rs
@@ -173,6 +173,10 @@ pub(super) fn fzf_v2(
     (slab, is_candidate_ascii): (&mut V2Slab, bool),
     ranges: &mut MatchedRanges,
 ) -> Option<Score> {
+    if pattern.is_empty() {
+        return Some(0);
+    }
+
     let (matches, last_match_offset) = matches(
         &mut slab.matched_indices,
         pattern,
diff --git a/tests/fzf_v2.rs b/tests/fzf_v2.rs
index 7bcfb29..a83a05b 100644
--- a/tests/fzf_v2.rs
+++ b/tests/fzf_v2.rs
@@ -237,3 +237,16 @@ fn fzf_v2_score_1() {
 
     assert_eq!(mach.matched_ranges().sorted(), [0..5]);
 }
+
+#[test]
+fn fzf_v2_score_2() {
+    let mut fzf = FzfV2::new()
+        .with_case_sensitivity(CaseSensitivity::Sensitive)
+        .with_matched_ranges(true);
+
+    let mut parser = FzfParser::new();
+
+    let mach = fzf.distance(parser.parse("!$"), "$$2");
+
+    assert!(mach.is_none());
+}