[String] Fix string conversion for -0.0 float values.

1 files changed, 16 insertions, 0 deletions

diff --git a/tests/core/string/test_string.h b/tests/core/string/test_string.h
index 659fb003d3..c10ad6e13d 100644
--- a/tests/core/string/test_string.h
+++ b/tests/core/string/test_string.h
@@ -805,6 +805,22 @@ TEST_CASE("[String] sprintf") {
 	REQUIRE(error == false);
 	CHECK(output == String("fish +99.990000 frog"));
 
+	// Real with sign (negative zero).
+	format = "fish %+f frog";
+	args.clear();
+	args.push_back(-0.0);
+	output = format.sprintf(args, &error);
+	REQUIRE(error == false);
+	CHECK(output == String("fish -0.000000 frog"));
+
+	// Real with sign (positive zero).
+	format = "fish %+f frog";
+	args.clear();
+	args.push_back(0.0);
+	output = format.sprintf(args, &error);
+	REQUIRE(error == false);
+	CHECK(output == String("fish +0.000000 frog"));
+
 	// Real with 1 decimal.
 	format = "fish %.1f frog";
 	args.clear();