fix #4312

and upgraded the test so that it would fail, both at compile time and at run time, without the fix

diff --git a/lib/dictBuilder/cover.c b/lib/dictBuilder/cover.c
index cfb756ff28e1349cf2851c4f4990c56322de16b3..ed750e31d65c1b163c28ff12860a828912bad218 100644 (file)
--- a/lib/dictBuilder/cover.c
+++ b/lib/dictBuilder/cover.c
@@ -284,7 +284,7 @@ static int COVER_cmp8(COVER_ctx_t *ctx, const void *lp, const void *rp) {
  */
 #if (defined(_WIN32) && defined(_MSC_VER)) || defined(__APPLE__)
 static int WIN_CDECL COVER_strict_cmp(void* g_coverCtx, const void* lp, const void* rp) {
-#elif defined(_GNU_SOURCE)
+#elif defined(_GNU_SOURCE) && !defined(ZSTD_USE_C90_QSORT)
 static int COVER_strict_cmp(const void *lp, const void *rp, void *g_coverCtx) {
 #else /* C90 fallback.*/
 static int COVER_strict_cmp(const void *lp, const void *rp) {
@@ -300,7 +300,7 @@ static int COVER_strict_cmp(const void *lp, const void *rp) {
  */
 #if (defined(_WIN32) && defined(_MSC_VER)) || defined(__APPLE__)
 static int WIN_CDECL COVER_strict_cmp8(void* g_coverCtx, const void* lp, const void* rp) {
-#elif defined(_GNU_SOURCE)
+#elif defined(_GNU_SOURCE) && !defined(ZSTD_USE_C90_QSORT)
 static int COVER_strict_cmp8(const void *lp, const void *rp, void *g_coverCtx) {
 #else /* C90 fallback.*/
 static int COVER_strict_cmp8(const void *lp, const void *rp) {