curl: remove compatibility code, require 7.29.0

cURL 7.16.0 was released in October 2006.  Just remove code that is
in all likelihood not being used anywhere, and require the oldest version
found in currently supported distros, which is 7.29.0 from CentOS 7.

pkg-config is enough for QEMU, since it does not need extra information
such as the path for certicate authorities.  All supported platforms
today will all have pkg-config for curl, so we can drop curl-config.

Suggested-by: Daniel Berrangé <berrange@redhat.com>
Reviewed-by: Daniel Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

block/curl.c

@@ -37,26 +37,6 @@
 
 // #define DEBUG_VERBOSE
 
-#if LIBCURL_VERSION_NUM >= 0x071000
-/* The multi interface timer callback was introduced in 7.16.0 */
-#define NEED_CURL_TIMER_CALLBACK
-#define HAVE_SOCKET_ACTION
-#endif
-
-#ifndef HAVE_SOCKET_ACTION
-/* If curl_multi_socket_action isn't available, define it statically here in
- * terms of curl_multi_socket. Note that ev_bitmask will be ignored, which is
- * less efficient but still safe. */
-static CURLMcode __curl_multi_socket_action(CURLM *multi_handle,
-                                            curl_socket_t sockfd,
-                                            int ev_bitmask,
-                                            int *running_handles)
-{
-    return curl_multi_socket(multi_handle, sockfd, running_handles);
-}
-#define curl_multi_socket_action __curl_multi_socket_action
-#endif
-
 #define PROTOCOLS (CURLPROTO_HTTP | CURLPROTO_HTTPS | \
                    CURLPROTO_FTP | CURLPROTO_FTPS)
 
@@ -140,7 +120,6 @@ typedef struct BDRVCURLState {
 static void curl_clean_state(CURLState *s);
 static void curl_multi_do(void *arg);
 
-#ifdef NEED_CURL_TIMER_CALLBACK
 /* Called from curl_multi_do_locked, with s->mutex held.  */
 static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
 {
@@ -156,7 +135,6 @@ static int curl_timer_cb(CURLM *multi, long timeout_ms, void *opaque)
     }
     return 0;
 }
-#endif
 
 /* Called from curl_multi_do_locked, with s->mutex held.  */
 static int curl_sock_cb(CURL *curl, curl_socket_t fd, int action,
@@ -433,7 +411,6 @@ static void curl_multi_do(void *arg)
 
 static void curl_multi_timeout_do(void *arg)
 {
-#ifdef NEED_CURL_TIMER_CALLBACK
     BDRVCURLState *s = (BDRVCURLState *)arg;
     int running;
 
@@ -446,9 +423,6 @@ static void curl_multi_timeout_do(void *arg)
 
     curl_multi_check_completion(s);
     qemu_mutex_unlock(&s->mutex);
-#else
-    abort();
-#endif
 }
 
 /* Called with s->mutex held.  */
@@ -598,10 +572,8 @@ static void curl_attach_aio_context(BlockDriverState *bs,
     s->multi = curl_multi_init();
     s->aio_context = new_context;
     curl_multi_setopt(s->multi, CURLMOPT_SOCKETFUNCTION, curl_sock_cb);
-#ifdef NEED_CURL_TIMER_CALLBACK
     curl_multi_setopt(s->multi, CURLMOPT_TIMERDATA, s);
     curl_multi_setopt(s->multi, CURLMOPT_TIMERFUNCTION, curl_timer_cb);
-#endif
 }
 
 static QemuOptsList runtime_opts = {

configure

@@ -3427,17 +3427,12 @@ done
 ##########################################
 # curl probe
 if test "$curl" != "no" ; then
-  if $pkg_config libcurl --exists; then
-    curlconfig="$pkg_config libcurl"
-  else
-    curlconfig=curl-config
-  fi
   cat > $TMPC << EOF
 #include <curl/curl.h>
 int main(void) { curl_easy_init(); curl_multi_setopt(0, 0, 0); return 0; }
 EOF
-  curl_cflags=$($curlconfig --cflags 2>/dev/null)
-  curl_libs=$($curlconfig --libs 2>/dev/null)
+  curl_cflags=$($pkg_config libcurl --cflags 2>/dev/null)
+  curl_libs=$($pkg_config libcurl --libs 2>/dev/null)
   if compile_prog "$curl_cflags" "$curl_libs" ; then
     curl=yes
   else