esp_http_server: fix few coverity warnings

- unreachable code
- uninitialized values
- missing return checks

components/esp_http_server/src/httpd_main.c

@@ -55,12 +55,16 @@ static esp_err_t httpd_accept_conn(struct httpd_data *hd, int listen_fd)
     /* Set recv timeout of this fd as per config */
     tv.tv_sec = hd->config.recv_wait_timeout;
     tv.tv_usec = 0;
-    setsockopt(new_fd, SOL_SOCKET, SO_RCVTIMEO, (const char *)&tv, sizeof(tv));
+    if (setsockopt(new_fd, SOL_SOCKET, SO_RCVTIMEO, (const char *)&tv, sizeof(tv)) < 0) {
+        ESP_LOGW(TAG, LOG_FMT("error enabling SO_RCVTIMEO (%d)"), errno);
+    }
 
     /* Set send timeout of this fd as per config */
     tv.tv_sec = hd->config.send_wait_timeout;
     tv.tv_usec = 0;
-    setsockopt(new_fd, SOL_SOCKET, SO_SNDTIMEO, (const char *)&tv, sizeof(tv));
+    if (setsockopt(new_fd, SOL_SOCKET, SO_SNDTIMEO, (const char *)&tv, sizeof(tv)) < 0) {
+        ESP_LOGW(TAG, LOG_FMT("error enabling SO_SNDTIMEO (%d)"), errno);
+    }
 
     if (ESP_OK != httpd_sess_new(hd, new_fd)) {
         ESP_LOGW(TAG, LOG_FMT("session creation failed"));

components/esp_http_server/src/httpd_parse.c

@@ -63,8 +63,9 @@ static esp_err_t verify_url (http_parser *parser)
     const char *at = parser_data->last.at;
     size_t  length = parser_data->last.length;
 
-    if ((r->method = parser->method) < 0) {
-        ESP_LOGW(TAG, LOG_FMT("HTTP Operation not supported"));
+    r->method = parser->method;
+    if (r->method < 0) {
+        ESP_LOGW(TAG, LOG_FMT("HTTP method not supported (%d)"), r->method);
         parser_data->error = HTTPD_501_METHOD_NOT_IMPLEMENTED;
         return ESP_FAIL;
     }
@@ -618,8 +619,8 @@ static esp_err_t httpd_parse_req(struct httpd_data *hd)
 {
     httpd_req_t *r = &hd->hd_req;
     int blk_len,  offset;
-    http_parser   parser;
-    parser_data_t parser_data;
+    http_parser   parser = {};
+    parser_data_t parser_data = {};
 
     /* Initialize parser */
     parse_init(r, &parser, &parser_data);

components/esp_http_server/src/httpd_sess.c

@@ -359,7 +359,9 @@ void httpd_sess_delete(struct httpd_data *hd, struct sock_db *session)
             .l_onoff = true,
             .l_linger = hd->config.linger_timeout,
         };
-        setsockopt(session->fd, SOL_SOCKET, SO_LINGER, &so_linger, sizeof(struct linger));
+        if (setsockopt(session->fd, SOL_SOCKET, SO_LINGER, &so_linger, sizeof(struct linger)) < 0) {
+            ESP_LOGW(TAG, LOG_FMT("error enabling SO_LINGER (%d)"), errno);
+        }
     }
 
     // Call close function if defined