git-curl-compat: remove check for curl 7.25.0

libcurl 7.25.0 was released in March 2012, which is well over ten years
ago, and no major operating system vendor is still providing security
support for it.  Debian 8, RHEL 7, and Ubuntu 12.10, all of which are
out of mainstream security support, have all supported a newer version.

Remove the check for this version and use this functionality
unconditionally.

Signed-off-by: brian m. carlson <[email protected]>
Signed-off-by: Taylor Blau <[email protected]>

Author: bk2204

git-curl-compat.h

@@ -28,14 +28,6 @@
  * introduced, oldest first, in the official version of cURL library.
  */
 
-/**
- * CURLOPT_TCP_KEEPALIVE was added in 7.25.0, released in March 2012.
- */
-#if LIBCURL_VERSION_NUM >= 0x071900
-#define GITCURL_HAVE_CURLOPT_TCP_KEEPALIVE 1
-#endif
-
-
 /**
  * CURLOPT_LOGIN_OPTIONS was added in 7.34.0, released in December
  * 2013.

http.c

@@ -716,35 +716,11 @@ static int has_proxy_cert_password(void)
 }
 #endif
 
-#ifdef GITCURL_HAVE_CURLOPT_TCP_KEEPALIVE
 static void set_curl_keepalive(CURL *c)
 {
 	curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
 }
 
-#else
-static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
-{
-	int ka = 1;
-	int rc;
-	socklen_t len = (socklen_t)sizeof(ka);
-
-	if (type != CURLSOCKTYPE_IPCXN)
-		return 0;
-
-	rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
-	if (rc < 0)
-		warning_errno("unable to set SO_KEEPALIVE on socket");
-
-	return CURL_SOCKOPT_OK;
-}
-
-static void set_curl_keepalive(CURL *c)
-{
-	curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
-}
-#endif
-
 /* Return 1 if redactions have been made, 0 otherwise. */
 static int redact_sensitive_header(struct strbuf *header, size_t offset)
 {