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, 3 insertions, 3 deletions

diff --git a/lib/http_chunks.c b/lib/http_chunks.c
index a267ad8f4..70db97e31 100644
--- a/lib/http_chunks.c
+++ b/lib/http_chunks.c
@@ -126,7 +126,7 @@ CHUNKcode Curl_httpchunk_read(struct connectdata *conn,
   /* the original data is written to the client, but we go on with the
      chunk read process, to properly calculate the content length*/
   if(data->set.http_te_skip && !k->ignorebody) {
-    result = Curl_client_write(conn, CLIENTWRITE_BODY, datap, datalen);
+    result = Curl_client_write(data, CLIENTWRITE_BODY, datap, datalen);
     if(result) {
       *extrap = result;
       return CHUNKE_PASSTHRU_ERROR;
@@ -198,7 +198,7 @@ CHUNKcode Curl_httpchunk_read(struct connectdata *conn,
         if(!conn->data->set.http_ce_skip && k->writer_stack)
           result = Curl_unencode_write(conn, k->writer_stack, datap, piece);
         else
-          result = Curl_client_write(conn, CLIENTWRITE_BODY, datap, piece);
+          result = Curl_client_write(data, CLIENTWRITE_BODY, datap, piece);
 
         if(result) {
           *extrap = result;
@@ -249,7 +249,7 @@ CHUNKcode Curl_httpchunk_read(struct connectdata *conn,
             return CHUNKE_BAD_CHUNK;
 
           if(!data->set.http_te_skip) {
-            result = Curl_client_write(conn, CLIENTWRITE_HEADER, tr, trlen);
+            result = Curl_client_write(data, CLIENTWRITE_HEADER, tr, trlen);
             if(result) {
               *extrap = result;
               return CHUNKE_PASSTHRU_ERROR;