doh: inherit some SSL options from user's easy handle

- Inherit SSL options for the doh handle but not SSL client certs,
  SSL ALPN/NPN, SSL engine, SSL version, SSL issuer cert,
  SSL pinned public key, SSL ciphers, SSL id cache setting,
  SSL kerberos or SSL gss-api settings.

- Fix inheritance of verbose setting.

- Inherit NOSIGNAL.

There is no way for the user to set options for the doh (DNS-over-HTTPS)
handles and instead we inherit some options from the user's easy handle.

My thinking for the SSL options not inherited is they are most likely
not intended by the user for the DOH transfer. I did inherit insecure
because I think that should still be in control of the user.

Prior to this change doh did not work for me because CAINFO was not
inherited. Also verbose was set always which AFAICT was a bug (#3660).

Fixes https://github.com/curl/curl/issues/3660
Closes https://github.com/curl/curl/pull/3661

lib/doh.c

@@ -173,8 +173,12 @@ static int Curl_doh_done(struct Curl_easy *doh, CURLcode result)
   return 0;
 }
 
-#define ERROR_CHECK_SETOPT(x,y) result = curl_easy_setopt(doh, x, y);   \
+#define ERROR_CHECK_SETOPT(x,y) \
-  if(result) goto error
+do {                                      \
+  result = curl_easy_setopt(doh, x, y);   \
+  if(result)                              \
+    goto error;                           \
+} WHILE_FALSE
 
 static CURLcode dohprobe(struct Curl_easy *data,
                          struct dnsprobe *p, DNStype dnstype,
@@ -242,7 +246,68 @@ static CURLcode dohprobe(struct Curl_easy *data,
     ERROR_CHECK_SETOPT(CURLOPT_PROTOCOLS, CURLPROTO_HTTPS);
 #endif
     ERROR_CHECK_SETOPT(CURLOPT_TIMEOUT_MS, (long)timeout_ms);
-    ERROR_CHECK_SETOPT(CURLOPT_VERBOSE, 1L);
+    if(data->set.verbose)
+      ERROR_CHECK_SETOPT(CURLOPT_VERBOSE, 1L);
+    if(data->set.no_signal)
+      ERROR_CHECK_SETOPT(CURLOPT_NOSIGNAL, 1L);
+
+    /* Inherit *some* SSL options from the user's transfer. This is a
+       best-guess as to which options are needed for compatibility. #3661 */
+    if(data->set.ssl.falsestart)
+      ERROR_CHECK_SETOPT(CURLOPT_SSL_FALSESTART, 1L);
+    if(data->set.ssl.primary.verifyhost)
+      ERROR_CHECK_SETOPT(CURLOPT_SSL_VERIFYHOST, 2L);
+    if(data->set.proxy_ssl.primary.verifyhost)
+      ERROR_CHECK_SETOPT(CURLOPT_PROXY_SSL_VERIFYHOST, 2L);
+    if(data->set.ssl.primary.verifypeer)
+      ERROR_CHECK_SETOPT(CURLOPT_SSL_VERIFYPEER, 1L);
+    if(data->set.proxy_ssl.primary.verifypeer)
+      ERROR_CHECK_SETOPT(CURLOPT_PROXY_SSL_VERIFYPEER, 1L);
+    if(data->set.ssl.primary.verifystatus)
+      ERROR_CHECK_SETOPT(CURLOPT_SSL_VERIFYSTATUS, 1L);
+    if(data->set.str[STRING_SSL_CAFILE_ORIG]) {
+      ERROR_CHECK_SETOPT(CURLOPT_CAINFO,
+        data->set.str[STRING_SSL_CAFILE_ORIG]);
+    }
+    if(data->set.str[STRING_SSL_CAFILE_PROXY]) {
+      ERROR_CHECK_SETOPT(CURLOPT_PROXY_CAINFO,
+        data->set.str[STRING_SSL_CAFILE_PROXY]);
+    }
+    if(data->set.str[STRING_SSL_CAPATH_ORIG]) {
+      ERROR_CHECK_SETOPT(CURLOPT_CAPATH,
+        data->set.str[STRING_SSL_CAPATH_ORIG]);
+    }
+    if(data->set.str[STRING_SSL_CAPATH_PROXY]) {
+      ERROR_CHECK_SETOPT(CURLOPT_PROXY_CAPATH,
+        data->set.str[STRING_SSL_CAPATH_PROXY]);
+    }
+    if(data->set.str[STRING_SSL_CRLFILE_ORIG]) {
+      ERROR_CHECK_SETOPT(CURLOPT_CRLFILE,
+        data->set.str[STRING_SSL_CRLFILE_ORIG]);
+    }
+    if(data->set.str[STRING_SSL_CRLFILE_PROXY]) {
+      ERROR_CHECK_SETOPT(CURLOPT_PROXY_CRLFILE,
+        data->set.str[STRING_SSL_CRLFILE_PROXY]);
+    }
+    if(data->set.ssl.certinfo)
+      ERROR_CHECK_SETOPT(CURLOPT_CERTINFO, 1L);
+    if(data->set.str[STRING_SSL_RANDOM_FILE]) {
+      ERROR_CHECK_SETOPT(CURLOPT_RANDOM_FILE,
+        data->set.str[STRING_SSL_RANDOM_FILE]);
+    }
+    if(data->set.str[STRING_SSL_EGDSOCKET]) {
+      ERROR_CHECK_SETOPT(CURLOPT_EGDSOCKET,
+        data->set.str[STRING_SSL_EGDSOCKET]);
+    }
+    if(data->set.ssl.no_revoke)
+      ERROR_CHECK_SETOPT(CURLOPT_SSL_OPTIONS, CURLSSLOPT_NO_REVOKE);
+    if(data->set.proxy_ssl.no_revoke)
+      ERROR_CHECK_SETOPT(CURLOPT_PROXY_SSL_OPTIONS, CURLSSLOPT_NO_REVOKE);
+    if(data->set.ssl.fsslctx)
+      ERROR_CHECK_SETOPT(CURLOPT_SSL_CTX_FUNCTION, data->set.ssl.fsslctx);
+    if(data->set.ssl.fsslctxp)
+      ERROR_CHECK_SETOPT(CURLOPT_SSL_CTX_DATA, data->set.ssl.fsslctxp);
+
     doh->set.fmultidone = Curl_doh_done;
     doh->set.dohfor = data; /* identify for which transfer this is done */
     p->easy = doh;