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tests: really test the non-var scalar inverse 

Function `test_inverse_scalar` contains:

    (var ? secp256k1_scalar_inverse_var : secp256k1_scalar_inverse_var)(&l, x);  /* l = 1/x */

The two sides of the condition are the same function. This seems to be
an error, as there also exists a non-var function, named
`secp256k1_scalar_inverse`.

Make `test_inverse_scalar` use this other function when `var` is false.

This issue was found using clang's static analyzer, which reported a
"Logic error: Identical expressions in conditional expression" (with
checker `alpha.core.IdenticalExpr`).
This commit is contained in:
Nicolas Iooss 2021-06-28 15:21:00 +02:00
parent 8ae56e33e7
commit 41ed13942b
1 changed files with 3 additions and 3 deletions
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6
src/tests.c
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@ -2595,7 +2595,7 @@ void test_inverse_scalar(secp256k1_scalar* out, const secp256k1_scalar* x, int v
{ {
secp256k1_scalar l, r, t; secp256k1_scalar l, r, t;
(var ? secp256k1_scalar_inverse_var : secp256k1_scalar_inverse_var)(&l, x); /* l = 1/x */ (var ? secp256k1_scalar_inverse_var : secp256k1_scalar_inverse)(&l, x); /* l = 1/x */
if (out) *out = l; if (out) *out = l;
if (secp256k1_scalar_is_zero(x)) { if (secp256k1_scalar_is_zero(x)) {
CHECK(secp256k1_scalar_is_zero(&l)); CHECK(secp256k1_scalar_is_zero(&l));
@ -2605,9 +2605,9 @@ void test_inverse_scalar(secp256k1_scalar* out, const secp256k1_scalar* x, int v
CHECK(secp256k1_scalar_is_one(&t)); /* x*(1/x) == 1 */ CHECK(secp256k1_scalar_is_one(&t)); /* x*(1/x) == 1 */
secp256k1_scalar_add(&r, x, &scalar_minus_one); /* r = x-1 */ secp256k1_scalar_add(&r, x, &scalar_minus_one); /* r = x-1 */
if (secp256k1_scalar_is_zero(&r)) return; if (secp256k1_scalar_is_zero(&r)) return;
(var ? secp256k1_scalar_inverse_var : secp256k1_scalar_inverse_var)(&r, &r); /* r = 1/(x-1) */ (var ? secp256k1_scalar_inverse_var : secp256k1_scalar_inverse)(&r, &r); /* r = 1/(x-1) */
secp256k1_scalar_add(&l, &scalar_minus_one, &l); /* l = 1/x-1 */ secp256k1_scalar_add(&l, &scalar_minus_one, &l); /* l = 1/x-1 */
(var ? secp256k1_scalar_inverse_var : secp256k1_scalar_inverse_var)(&l, &l); /* l = 1/(1/x-1) */ (var ? secp256k1_scalar_inverse_var : secp256k1_scalar_inverse)(&l, &l); /* l = 1/(1/x-1) */
secp256k1_scalar_add(&l, &l, &secp256k1_scalar_one); /* l = 1/(1/x-1)+1 */ secp256k1_scalar_add(&l, &l, &secp256k1_scalar_one); /* l = 1/(1/x-1)+1 */
secp256k1_scalar_add(&l, &r, &l); /* l = 1/(1/x-1)+1 + 1/(x-1) */ secp256k1_scalar_add(&l, &r, &l); /* l = 1/(1/x-1)+1 + 1/(x-1) */
CHECK(secp256k1_scalar_is_zero(&l)); /* l == 0 */ CHECK(secp256k1_scalar_is_zero(&l)); /* l == 0 */