lib: pass in 'struct Curl_easy *' to most functions

... in most cases instead of 'struct connectdata *' but in some cases in
addition to.

- We mostly operate on transfers and not connections.

- We need the transfer handle to log, store data and more. Everything in
  libcurl is driven by a transfer (the CURL * in the public API).

- This work clarifies and separates the transfers from the connections
  better.

- We should avoid "conn->data". Since individual connections can be used
  by many transfers when multiplexing, making sure that conn->data
  points to the current and correct transfer at all times is difficult
  and has been notoriously error-prone over the years. The goal is to
  ultimately remove the conn->data pointer for this reason.

Closes #6425

1 files changed, 1 insertions, 1 deletions

diff --git a/lib/hostip.c b/lib/hostip.c
index eaa0bdbc3..a3f6090ab 100644
--- a/lib/hostip.c
+++ b/lib/hostip.c
@@ -565,7 +565,7 @@ enum resolve_t Curl_resolv(struct connectdata *conn,
     if(!addr) {
       /* Check what IP specifics the app has requested and if we can provide
        * it. If not, bail out. */
-      if(!Curl_ipvalid(conn))
+      if(!Curl_ipvalid(data, conn))
         return CURLRESOLV_ERROR;
 
       if(allowDOH && data->set.doh && !ipnum) {