vendor/libsodium/src/libsodium/crypto_scalarmult/curve25519/scalarmult_curve25519.c in rbnacl-libsodium-1.0.13 vs vendor/libsodium/src/libsodium/crypto_scalarmult/curve25519/scalarmult_curve25519.c in rbnacl-libsodium-1.0.15

@@ -18,14 +18,14 @@
 
 int
 crypto_scalarmult_curve25519(unsigned char *q, const unsigned char *n,
                              const unsigned char *p)
 {
-    size_t        i;
-    unsigned char d = 0;
+    size_t                 i;
+    volatile unsigned char d = 0;
 
     if (implementation->mult(q, n, p) != 0) {
-        return -1;
+        return -1; /* LCOV_EXCL_LINE */
     }
     for (i = 0; i < crypto_scalarmult_curve25519_BYTES; i++) {
         d |= q[i];
     }
     return -(1 & ((d - 1) >> 8));