From 023bae737c7dcfda2fa4efac04d969d7c4366b41 Mon Sep 17 00:00:00 2001
From: Anna Schumaker <Anna@OcarinaProject.net>
Date: Thu, 24 Sep 2015 13:57:42 -0400
Subject: [PATCH] core/string: Add a function for comparing strings

And switch over the GenericTag to using it.

Signed-off-by: Anna Schumaker <Anna@OcarinaProject.net>
---
 core/string.c         | 12 ++++++++++++
 core/tags/generic.cpp |  6 +-----
 include/core/string.h |  9 +++++++++
 tests/core/string.c   | 12 ++++++++++++
 4 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/core/string.c b/core/string.c
index dfa1a43d..be6ad6ba 100644
--- a/core/string.c
+++ b/core/string.c
@@ -64,3 +64,15 @@ gchar *string_lowercase(const gchar *str)
 
 	return res;
 }
+
+int string_compare(const gchar *lhs, const gchar *rhs)
+{
+	if (strlen(lhs) == 0) {
+		if (strlen(rhs) == 0)
+			return 0;
+		return 1;
+	}
+	if (strlen(rhs) == 0)
+		return -1;
+	return g_strcmp0(lhs, rhs);
+}
diff --git a/core/tags/generic.cpp b/core/tags/generic.cpp
index e446ed48..650449b0 100644
--- a/core/tags/generic.cpp
+++ b/core/tags/generic.cpp
@@ -53,9 +53,5 @@ const std::string &GenericTag :: lowercase()
 
 int GenericTag :: compare(const GenericTag *rhs)
 {
-	if (_lower.size() == 0)
-		return 1;
-	if (rhs->_lower.size() == 0)
-		return -1;
-	return _lower.compare(rhs->_lower);
+	return string_compare(_lower.c_str(), rhs->_lower.c_str());
 }
diff --git a/include/core/string.h b/include/core/string.h
index 7b6ed084..f97828d3 100644
--- a/include/core/string.h
+++ b/include/core/string.h
@@ -20,4 +20,13 @@ gchar *string_sec2str_long(unsigned int);
 /* Convert the input string to lowercase, dropping special characters. */
 gchar *string_lowercase(const gchar *);
 
+/*
+ * Compare two strings.
+ *
+ * if ret < 0: lhs < rhs, or rhs is empty.
+ * if ret = 0: lhs == rhs.
+ * if ret > 0: lhs > rhs, or lhs is empty.
+ */
+int string_compare(const gchar *, const gchar *);
+
 #endif /* OCARINA_CORE_STRING_H */
diff --git a/tests/core/string.c b/tests/core/string.c
index 9cb33ea4..fef40770 100644
--- a/tests/core/string.c
+++ b/tests/core/string.c
@@ -69,11 +69,23 @@ void test_lowercase()
 	test_equal(swap(string_lowercase("!  __test(TEXT) + __test(\"TEXT\")")),
 					"test text test text");
 	test_equal(swap(string_lowercase("Test~tEXt\\123")), "test text 123");
+}
 
+void test_compare()
+{
+	test_equal(string_compare("A", "A"),  0);
+	test_equal(string_compare("a", "a"),  0);
+	test_equal(string_compare("A", "B"), -1);
+	test_equal(string_compare("B", "A"),  1);
+
+	test_equal(string_compare("", ""),   0);
+	test_equal(string_compare("", "A"),  1);
+	test_equal(string_compare("A", ""), -1);
 }
 
 DECLARE_UNIT_TESTS(
 	UNIT_TEST("Seconds to String", test_sec2str),
 	UNIT_TEST("Seconds to String (Long)", test_sec2str_long),
 	UNIT_TEST("String Lowercase", test_lowercase),
+	UNIT_TEST("String Comparison", test_compare),
 );