From 9d7a1e3bb319f6b603affb6a3d391148d60e89f9 Mon Sep 17 00:00:00 2001
From: Fangrui Song <i@maskray.me>
Date: Thu, 20 Dec 2018 00:00:42 -0800
Subject: [PATCH] fuzzy_match: a pattern prefixed with a letter should not
 match underscore prefixed builtin names

---
 src/fuzzy_match.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/fuzzy_match.cc b/src/fuzzy_match.cc
index 680aa4ac..b377d586 100644
--- a/src/fuzzy_match.cc
+++ b/src/fuzzy_match.cc
@@ -108,6 +108,8 @@ FuzzyMatcher::FuzzyMatcher(std::string_view pattern, int sensitivity) {
 }
 
 int FuzzyMatcher::Match(std::string_view text) {
+  if (pat.empty() != text.empty())
+    return kMinScore;
   int n = int(text.size());
   if (n > kMaxText)
     return kMinScore + 1;
@@ -115,6 +117,8 @@ int FuzzyMatcher::Match(std::string_view text) {
   for (int i = 0; i < n; i++)
     low_text[i] = ::tolower(text[i]);
   CalculateRoles(text, text_role, &text_set);
+  if (n && !!pat_role[0] != !!text_role[0])
+    return kMinScore;
   dp[0][0][0] = dp[0][0][1] = 0;
   for (int j = 0; j < n; j++) {
     dp[0][j + 1][0] = dp[0][j][0] + MissScore(j, false);