Fix SSL_set_{min,max}_proto_version APIs in invalid versions.

SSL_set_max_proto_version(TLS1_3_DRAFT_VERSION) worked unintentionally.
Fix that. Also add an error when it fails.

Change-Id: I1048fede7b163e1c170e17bf4370b468221a7077
Reviewed-on: https://boringssl-review.googlesource.com/17525
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
diff --git a/ssl/ssl_test.cc b/ssl/ssl_test.cc
index 84b7496..7737e75 100644
--- a/ssl/ssl_test.cc
+++ b/ssl/ssl_test.cc
@@ -2567,6 +2567,10 @@
   EXPECT_TRUE(SSL_CTX_set_max_proto_version(ctx.get(), TLS1_3_VERSION));
   EXPECT_EQ(TLS1_3_VERSION, ctx->conf_max_version);
 
+  // TLS1_3_DRAFT_VERSION is not an API-level version.
+  EXPECT_FALSE(SSL_CTX_set_max_proto_version(ctx.get(), TLS1_3_DRAFT_VERSION));
+  ERR_clear_error();
+
   ctx.reset(SSL_CTX_new(DTLS_method()));
   ASSERT_TRUE(ctx);