http: fix `-Wunused-variable` compiler warning

Fix compiler warnings in builds with disabled auths, NTLM and SPNEGO.

E.g. with `CURL_DISABLE_BASIC_AUTH` + `CURL_DISABLE_BEARER_AUTH` +
`CURL_DISABLE_DIGEST_AUTH` + `CURL_DISABLE_NEGOTIATE_AUTH` +
`CURL_DISABLE_NTLM` on non-Windows.

```
./curl/lib/http.c:737:12: warning: unused variable 'result' [-Wunused-variable]
  CURLcode result = CURLE_OK;
           ^
./curl/lib/http.c:995:18: warning: variable 'availp' set but not used [-Wunused-but-set-variable]
  unsigned long *availp;
                 ^
./curl/lib/http.c:996:16: warning: variable 'authp' set but not used [-Wunused-but-set-variable]
  struct auth *authp;
               ^
```

Regression from e92edfbef64448ef461117769881f3ed776dec4e #11490

Fixes #12228
Closes #12335

diff --git a/lib/http.c b/lib/http.c
index c4af629954240d9d88a794320a6ad3a5876b8f8c..c886e14dc7c6b786929c8452b73c0c6543b7aeca 100644 (file)
--- a/lib/http.c
+++ b/lib/http.c
@@ -845,7 +845,7 @@ output_auth_headers(struct Curl_easy *data,
   else
     authstatus->multipass = FALSE;
 
-  return CURLE_OK;
+  return result;
 }
 
 /**
@@ -996,11 +996,15 @@ CURLcode Curl_http_input_auth(struct Curl_easy *data, bool proxy,
   curlnegotiate *negstate = proxy ? &conn->proxy_negotiate_state :
                                     &conn->http_negotiate_state;
 #endif
+#if defined(USE_SPNEGO) || \
+  defined(USE_NTLM) || \
+  !defined(CURL_DISABLE_DIGEST_AUTH) || \
+  !defined(CURL_DISABLE_BASIC_AUTH) || \
+  !defined(CURL_DISABLE_BEARER_AUTH)
+
   unsigned long *availp;
   struct auth *authp;
 
-  (void) conn; /* In case conditionals make it unused. */
-
   if(proxy) {
     availp = &data->info.proxyauthavail;
     authp = &data->state.authproxy;
@@ -1009,6 +1013,11 @@ CURLcode Curl_http_input_auth(struct Curl_easy *data, bool proxy,
     availp = &data->info.httpauthavail;
     authp = &data->state.authhost;
   }
+#else
+  (void) proxy;
+#endif
+
+  (void) conn; /* In case conditionals make it unused. */
 
   /*
    * Here we check if we want the specific single authentication (using ==) and