fix(libc): return success for heapsort with at most one element regardless of size

core/libs/prx/libc/src/FileAndHeap.cpp

@@ -753,11 +753,11 @@ int APS5_VABI mergesort_nid_postfix(void* base, size_t count, size_t size, Guest
 }
 
 int APS5_VABI heapsort_nid_postfix(void* base, size_t count, size_t size, GuestCompare compare) {
+    if (count <= 1) return 0;
     if (size == 0) {
         errno = 22;
         return -1;
     }
-    if (count <= 1) return 0;
     if (!compare) throw std::invalid_argument("heapsort: null comparator");
     if (!base) throw std::invalid_argument("heapsort: null base");
     if (count > std::numeric_limits<size_t>::max() / size) throw std::overflow_error("heapsort: array size overflow");

core/libs/tests/GuestQsort.cpp

@@ -225,6 +225,9 @@ bool CheckHeapsort() {
     }
     unsigned char bytes[3] = {3, 1, 2};
     *__error_nid_postfix() = 0;
+    correct &= heapsort_nid_postfix(nullptr, 0, 0, nullptr) == 0;
+    unsigned char single = 42;
+    correct &= heapsort_nid_postfix(&single, 1, 0, nullptr) == 0;
     correct &= heapsort_nid_postfix(bytes, 3, 0, CompareFirstByte) == -1 && *__error_nid_postfix() == 22 && bytes[0] == 3;
     correct &= heapsort_nid_postfix(nullptr, 0, 4, CompareKeys) == 0;
     if (!correct) std::fprintf(stderr, "heapsort failed\n");