a couple more tests

glfw/backend_utils.c

@@ -15,7 +15,6 @@
 #include <unistd.h>
 #include <fcntl.h>
 #include <errno.h>
-#include <float.h>
 #include <time.h>
 #include <stdio.h>
 

kitty_tests/glfw.py

@@ -82,3 +82,5 @@ class TestGLFW(BaseTest):
         test('>ế<')
         test('>𐍈<')
         test('∮ E⋅da = Q,  n → ∞, 𐍈∑ f(i) = ∏ g(i)')
+        self.ae(utf_8_strndup(b'\xf0\x9f\x98\xb8', 3).value, b'')
+        self.ae(utf_8_strndup(b'\xc3\xb6\xf0\x9f\x98\xb8', 4).value, b'\xc3\xb6')