src/http/ngx_http_upstream.c:1395: error: Uninitialized Value
  The value read from rc was never initialized.

src/http/ngx_http_upstream.c:1395:9: 
1393.     }
1394. 
1395.     if (rc == NGX_HTTP_UPSTREAM_INVALID_HEADER) {
              ^
1396.         ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_INVALID_HEADER);
1397.         return;

static void
ngx_http_upstream_process_header(ngx_http_request_t *r, ngx_http_upstream_t *u)
{
    ssize_t            n;
    ngx_int_t          rc;
    ngx_connection_t  *c;
    c = u->peer.connection;
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http upstream process header");
    c->log->action = "reading response header from upstream";
    if (c->read->timedout) {
        ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_TIMEOUT);
        return;
    }
    if (!u->request_sent && ngx_http_upstream_test_connect(c) != NGX_OK) {
        ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_ERROR);
        return;
    }
    if (u->buffer.start == NULL) {
        u->buffer.start = ngx_palloc(r->pool, u->conf->buffer_size);
        if (u->buffer.start == NULL) {
            ngx_http_upstream_finalize_request(r, u,
                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
            return;
        }
        u->buffer.pos = u->buffer.start;
        u->buffer.last = u->buffer.start;
        u->buffer.end = u->buffer.start + u->conf->buffer_size;
        u->buffer.temporary = 1;
        u->buffer.tag = u->output.tag;
        if (ngx_list_init(&u->headers_in.headers, r->pool, 8,
                          sizeof(ngx_table_elt_t))
            != NGX_OK)
        {
            ngx_http_upstream_finalize_request(r, u,
                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
            return;
        }
#if (NGX_HTTP_CACHE)
        if (r->cache) {
            u->buffer.pos += r->cache->header_start;
            u->buffer.last = u->buffer.pos;
        }
#endif
    }
    for ( ;; ) {
        n = c->recv(c, u->buffer.last, u->buffer.end - u->buffer.last);
        if (n == NGX_AGAIN) {
#if 0
            ngx_add_timer(rev, u->read_timeout);
#endif
            if (ngx_handle_read_event(c->read, 0) != NGX_OK) {
                ngx_http_upstream_finalize_request(r, u,
                                               NGX_HTTP_INTERNAL_SERVER_ERROR);
                return;
            }
            return;
        }
        if (n == 0) {
            ngx_log_error(NGX_LOG_ERR, c->log, 0,
                          "upstream prematurely closed connection");
        }
        if (n == NGX_ERROR || n == 0) {
            ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_ERROR);
            return;
        }
        u->buffer.last += n;
#if 0
        u->valid_header_in = 0;
        u->peer.cached = 0;
#endif
        rc = u->process_header(r);
        if (rc == NGX_AGAIN) {
            if (u->buffer.pos == u->buffer.end) {
                ngx_log_error(NGX_LOG_ERR, c->log, 0,
                              "upstream sent too big header");
                ngx_http_upstream_next(r, u,
                                       NGX_HTTP_UPSTREAM_FT_INVALID_HEADER);
                return;
            }
            continue;
        }
        break;
    }
    if (rc == NGX_HTTP_UPSTREAM_INVALID_HEADER) {
        ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_INVALID_HEADER);
        return;
    }
    if (rc == NGX_ERROR) {
        ngx_http_upstream_finalize_request(r, u,
                                           NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
    }
    if (u->headers_in.status_n >= NGX_HTTP_BAD_REQUEST) {
        if (r->subrequest_in_memory) {
            u->buffer.last = u->buffer.pos;
        }
        if (ngx_http_upstream_test_next(r, u) == NGX_OK) {
            return;
        }
        if (ngx_http_upstream_intercept_errors(r, u) == NGX_OK) {
            return;
        }
    }
    if (ngx_http_upstream_process_headers(r, u) != NGX_OK) {
        return;
    }
    if (!r->subrequest_in_memory) {
        ngx_http_upstream_send_response(r, u);
        return;
    }
    if (u->input_filter == NULL) {
        u->input_filter_init = ngx_http_upstream_non_buffered_filter_init;
        u->input_filter = ngx_http_upstream_non_buffered_filter;
        u->input_filter_ctx = r;
    }
    if (u->input_filter_init(u->input_filter_ctx) == NGX_ERROR) {
        ngx_http_upstream_finalize_request(r, u,
                                           NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
    }
    n = u->buffer.last - u->buffer.pos;
    if (n) {
        u->buffer.last -= n;
        u->state->response_length += n;
        if (u->input_filter(u->input_filter_ctx, n) == NGX_ERROR) {
            ngx_http_upstream_finalize_request(r, u, NGX_ERROR);
            return;
        }
        if (u->length == 0) {
            ngx_http_upstream_finalize_request(r, u, 0);
            return;
        }
    }
    u->read_event_handler = ngx_http_upstream_process_body_in_memory;
    ngx_http_upstream_process_body_in_memory(r, u);
}
['static void\nngx_http_upstream_process_header(ngx_http_request_t *r, ngx_http_upstream_t *u)\n{\n    ssize_t            n;\n    ngx_int_t          rc;\n    ngx_connection_t  *c;\n    c = u->peer.connection;\n    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,\n                   "http upstream process header");\n    c->log->action = "reading response header from upstream";\n    if (c->read->timedout) {\n        ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_TIMEOUT);\n        return;\n    }\n    if (!u->request_sent && ngx_http_upstream_test_connect(c) != NGX_OK) {\n        ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_ERROR);\n        return;\n    }\n    if (u->buffer.start == NULL) {\n        u->buffer.start = ngx_palloc(r->pool, u->conf->buffer_size);\n        if (u->buffer.start == NULL) {\n            ngx_http_upstream_finalize_request(r, u,\n                                               NGX_HTTP_INTERNAL_SERVER_ERROR);\n            return;\n        }\n        u->buffer.pos = u->buffer.start;\n        u->buffer.last = u->buffer.start;\n        u->buffer.end = u->buffer.start + u->conf->buffer_size;\n        u->buffer.temporary = 1;\n        u->buffer.tag = u->output.tag;\n        if (ngx_list_init(&u->headers_in.headers, r->pool, 8,\n                          sizeof(ngx_table_elt_t))\n            != NGX_OK)\n        {\n            ngx_http_upstream_finalize_request(r, u,\n                                               NGX_HTTP_INTERNAL_SERVER_ERROR);\n            return;\n        }\n#if (NGX_HTTP_CACHE)\n        if (r->cache) {\n            u->buffer.pos += r->cache->header_start;\n            u->buffer.last = u->buffer.pos;\n        }\n#endif\n    }\n    for ( ;; ) {\n        n = c->recv(c, u->buffer.last, u->buffer.end - u->buffer.last);\n        if (n == NGX_AGAIN) {\n#if 0\n            ngx_add_timer(rev, u->read_timeout);\n#endif\n            if (ngx_handle_read_event(c->read, 0) != NGX_OK) {\n                ngx_http_upstream_finalize_request(r, u,\n                                               NGX_HTTP_INTERNAL_SERVER_ERROR);\n                return;\n            }\n            return;\n        }\n        if (n == 0) {\n            ngx_log_error(NGX_LOG_ERR, c->log, 0,\n                          "upstream prematurely closed connection");\n        }\n        if (n == NGX_ERROR || n == 0) {\n            ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_ERROR);\n            return;\n        }\n        u->buffer.last += n;\n#if 0\n        u->valid_header_in = 0;\n        u->peer.cached = 0;\n#endif\n        rc = u->process_header(r);\n        if (rc == NGX_AGAIN) {\n            if (u->buffer.pos == u->buffer.end) {\n                ngx_log_error(NGX_LOG_ERR, c->log, 0,\n                              "upstream sent too big header");\n                ngx_http_upstream_next(r, u,\n                                       NGX_HTTP_UPSTREAM_FT_INVALID_HEADER);\n                return;\n            }\n            continue;\n        }\n        break;\n    }\n    if (rc == NGX_HTTP_UPSTREAM_INVALID_HEADER) {\n        ngx_http_upstream_next(r, u, NGX_HTTP_UPSTREAM_FT_INVALID_HEADER);\n        return;\n    }\n    if (rc == NGX_ERROR) {\n        ngx_http_upstream_finalize_request(r, u,\n                                           NGX_HTTP_INTERNAL_SERVER_ERROR);\n        return;\n    }\n    if (u->headers_in.status_n >= NGX_HTTP_BAD_REQUEST) {\n        if (r->subrequest_in_memory) {\n            u->buffer.last = u->buffer.pos;\n        }\n        if (ngx_http_upstream_test_next(r, u) == NGX_OK) {\n            return;\n        }\n        if (ngx_http_upstream_intercept_errors(r, u) == NGX_OK) {\n            return;\n        }\n    }\n    if (ngx_http_upstream_process_headers(r, u) != NGX_OK) {\n        return;\n    }\n    if (!r->subrequest_in_memory) {\n        ngx_http_upstream_send_response(r, u);\n        return;\n    }\n    if (u->input_filter == NULL) {\n        u->input_filter_init = ngx_http_upstream_non_buffered_filter_init;\n        u->input_filter = ngx_http_upstream_non_buffered_filter;\n        u->input_filter_ctx = r;\n    }\n    if (u->input_filter_init(u->input_filter_ctx) == NGX_ERROR) {\n        ngx_http_upstream_finalize_request(r, u,\n                                           NGX_HTTP_INTERNAL_SERVER_ERROR);\n        return;\n    }\n    n = u->buffer.last - u->buffer.pos;\n    if (n) {\n        u->buffer.last -= n;\n        u->state->response_length += n;\n        if (u->input_filter(u->input_filter_ctx, n) == NGX_ERROR) {\n            ngx_http_upstream_finalize_request(r, u, NGX_ERROR);\n            return;\n        }\n        if (u->length == 0) {\n            ngx_http_upstream_finalize_request(r, u, 0);\n            return;\n        }\n    }\n    u->read_event_handler = ngx_http_upstream_process_body_in_memory;\n    ngx_http_upstream_process_body_in_memory(r, u);\n}']