From 74ce20b25652adefaf3a715703bb4bd92adcbc86 Mon Sep 17 00:00:00 2001
From: "Michael Cook (mackal)" <mcook@mackal.net>
Date: Tue, 23 Feb 2021 12:52:34 -0500
Subject: [PATCH] Add string util search_deliminated_string (#1260)

This function takes a string of deliminated an see if another string is
one of those

This function also verifies it's not finding a substring
---
 common/string_util.cpp   | 13 +++++++++++++
 common/string_util.h     |  1 +
 tests/string_util_test.h | 28 ++++++++++++++++++++++++++++
 3 files changed, 42 insertions(+)

diff --git a/common/string_util.cpp b/common/string_util.cpp
index 7cd19c829..d236f6532 100644
--- a/common/string_util.cpp
+++ b/common/string_util.cpp
@@ -125,6 +125,19 @@ std::vector<std::string> SplitString(const std::string &str, char delim) {
 	return ret;
 }
 
+std::string::size_type search_deliminated_string(const std::string &haystack, const std::string &needle, const char deliminator)
+{
+	// this shouldn't go out of bounds, even without obvious bounds checks
+	auto pos = haystack.find(needle);
+	while (pos != std::string::npos) {
+		auto c = haystack[pos + needle.length()];
+		if ((c == '\0' || c == deliminator) && (pos == 0 || haystack[pos - 1] == deliminator))
+			return pos;
+		pos = haystack.find(needle, pos + needle.length());
+	}
+	return std::string::npos;
+}
+
 std::string implode(std::string glue, std::vector<std::string> src)
 {
 	if (src.empty()) {
diff --git a/common/string_util.h b/common/string_util.h
index 226e21645..6ccaf7125 100644
--- a/common/string_util.h
+++ b/common/string_util.h
@@ -178,6 +178,7 @@ std::vector<std::string> join_tuple(const std::string &glue, const std::pair<cha
 }
 
 std::vector<std::string> SplitString(const std::string &s, char delim);
+std::string::size_type search_deliminated_string(const std::string &haystack, const std::string &needle, const char deliminator = ',');
 std::string EscapeString(const char *src, size_t sz);
 std::string EscapeString(const std::string &s);
 bool StringIsNumber(const std::string &s);
diff --git a/tests/string_util_test.h b/tests/string_util_test.h
index facb0cc72..0333d0391 100644
--- a/tests/string_util_test.h
+++ b/tests/string_util_test.h
@@ -29,6 +29,7 @@ public:
 		TEST_ADD(StringUtilTest::StringFormatTest);
 		TEST_ADD(StringUtilTest::EscapeStringTest);
 		TEST_ADD(StringUtilTest::EscapeStringMemoryTest);
+		TEST_ADD(StringUtilTest::SearchDeliminatedStringTest);
 	}
 
 	~StringUtilTest() {
@@ -80,6 +81,33 @@ public:
 		auto s = EscapeString(t, 10);
 		TEST_ASSERT(s.compare("abc\\x00\\n\\r\\\\\\'\\\"\\x1a") == 0);
 	}
+
+	void SearchDeliminatedStringTest() {
+		std::string h =
+		    "befallen,charasis,dalnir,frontiermtns,gukbottom,iceclad,lakeofillomen,northkarana,qey2hh1,soldunga,southro,wakening,podisease,velketor,akheva,riwwi,bothunder,poair";
+		TEST_ASSERT(search_deliminated_string(h, "befallen") == 0);
+		TEST_ASSERT(search_deliminated_string(h, "charasis") == 9);
+		TEST_ASSERT(search_deliminated_string(h, "dalnir") == 18);
+		TEST_ASSERT(search_deliminated_string(h, "frontiermtns") == 25);
+		TEST_ASSERT(search_deliminated_string(h, "gukbottom") == 38);
+		TEST_ASSERT(search_deliminated_string(h, "iceclad") == 48);
+		TEST_ASSERT(search_deliminated_string(h, "lakeofillomen") == 56);
+		TEST_ASSERT(search_deliminated_string(h, "northkarana") == 70);
+		TEST_ASSERT(search_deliminated_string(h, "qey2hh1") == 82);
+		TEST_ASSERT(search_deliminated_string(h, "soldunga") == 90);
+		TEST_ASSERT(search_deliminated_string(h, "southro") == 99);
+		TEST_ASSERT(search_deliminated_string(h, "wakening") == 107);
+		TEST_ASSERT(search_deliminated_string(h, "podisease") == 116);
+		TEST_ASSERT(search_deliminated_string(h, "velketor") == 126);
+		TEST_ASSERT(search_deliminated_string(h, "akheva") == 135);
+		TEST_ASSERT(search_deliminated_string(h, "riwwi") == 142);
+		TEST_ASSERT(search_deliminated_string(h, "bothunder") == 148);
+		TEST_ASSERT(search_deliminated_string(h, "poair") == 158);
+		TEST_ASSERT(search_deliminated_string(h, "pod") == std::string::npos);
+		TEST_ASSERT(search_deliminated_string(h, "air") == std::string::npos);
+		TEST_ASSERT(search_deliminated_string(h, "bef") == std::string::npos);
+		TEST_ASSERT(search_deliminated_string(h, "wwi") == std::string::npos);
+	}
 };
 
 #endif