[PATCH 2/2] imap-send: not define USE_CURL_FOR_IMAP_SEND in Makefile

[Jiang Xin <worldhello.net@gmail.com>]

From: Jiang Xin <zhiyou.jx@alibaba-inc.com>

The definition and using of macro "USE_CURL_FOR_IMAP_SEND" are at
different locations. It is defined in Makefile and is used in file
"imap-send.c". Even though we have fixed the mismatched "curl_config"
issue in Makefile in the previous commit, moving the definition of the
macro "USE_CURL_FOR_IMAP_SEND" to souce code "imap-send.c" seems more
nature and may help us to use curl in imap-send by force in future by
removing "USE_CURL_FOR_IMAP_SEND".

The side effect of this change is that the "git-imap-send" program may
be larger than necessary if we have a lower version of libcurl
installed.

Signed-off-by: Jiang Xin <zhiyou.jx@alibaba-inc.com>
---
 Makefile                            | 11 ++---------
 contrib/buildsystems/CMakeLists.txt |  3 ---
 imap-send.c                         | 29 +++++++++++++++++------------
 3 files changed, 19 insertions(+), 24 deletions(-)

diff --git a/Makefile b/Makefile
index f4eaf22523..83721216fc 100644
--- a/Makefile
+++ b/Makefile
@@ -1621,15 +1621,8 @@ else
 	ifndef NO_EXPAT
 		PROGRAM_OBJS += http-push.o
 	endif
-	curl_check := $(shell (echo 072200; $(CURL_CONFIG) --vernum | sed -e '/^70[BC]/s/^/0/') 2>/dev/null | sort -r | sed -ne 2p)
-	ifeq "$(curl_check)" "072200"
-		USE_CURL_FOR_IMAP_SEND = YesPlease
-	endif
-	ifdef USE_CURL_FOR_IMAP_SEND
-		BASIC_CFLAGS += -DUSE_CURL_FOR_IMAP_SEND
-		IMAP_SEND_BUILDDEPS = http.o
-		IMAP_SEND_LDFLAGS += $(CURL_LIBCURL)
-	endif
+	IMAP_SEND_BUILDDEPS = http.o
+	IMAP_SEND_LDFLAGS += $(CURL_LIBCURL)
 	ifndef NO_EXPAT
 		ifdef EXPATDIR
 			BASIC_CFLAGS += -I$(EXPATDIR)/include
diff --git a/contrib/buildsystems/CMakeLists.txt b/contrib/buildsystems/CMakeLists.txt
index 2f6e0197ff..d508db4d29 100644
--- a/contrib/buildsystems/CMakeLists.txt
+++ b/contrib/buildsystems/CMakeLists.txt
@@ -622,9 +622,6 @@ if(NOT CURL_FOUND)
 	message(WARNING "git-http-push and git-http-fetch will not be built")
 else()
 	list(APPEND PROGRAMS_BUILT git-http-fetch git-http-push git-imap-send git-remote-http)
-	if(CURL_VERSION_STRING VERSION_GREATER_EQUAL 7.34.0)
-		add_compile_definitions(USE_CURL_FOR_IMAP_SEND)
-	endif()
 endif()
 
 if(NOT EXPAT_FOUND)
diff --git a/imap-send.c b/imap-send.c
index a50af56b82..c0a2c2b4e6 100644
--- a/imap-send.c
+++ b/imap-send.c
@@ -30,20 +30,25 @@
 #if defined(NO_OPENSSL) && !defined(HAVE_OPENSSL_CSPRNG)
 typedef void *SSL;
 #endif
-#ifdef USE_CURL_FOR_IMAP_SEND
+#ifdef NO_CURL
+#define USE_CURL_FOR_IMAP_SEND 0
+#else
 #include "http.h"
-#endif
-
-#if defined(USE_CURL_FOR_IMAP_SEND)
-/* Always default to curl if it's available. */
-#define USE_CURL_DEFAULT 1
+/*
+ * Since version 7.30.0, libcurl's API has been able to communicate with
+ * IMAP servers, and curl's CURLOPT_LOGIN_OPTIONS (enabling IMAP
+ * authentication) parameter is available if curl's version is >= 7.34.0,
+ * Always use curl if there is a matching libcurl.
+ */
+#if LIBCURL_VERSION_NUM >= 0x072200
+#define USE_CURL_FOR_IMAP_SEND 1
 #else
-/* We don't have curl, so continue to use the historical implementation */
-#define USE_CURL_DEFAULT 0
+#define USE_CURL_FOR_IMAP_SEND 0
+#endif
 #endif
 
 static int verbosity;
-static int use_curl = USE_CURL_DEFAULT;
+static int use_curl = USE_CURL_FOR_IMAP_SEND;
 
 static const char * const imap_send_usage[] = { "git imap-send [-v] [-q] [--[no-]curl] < <mbox>", NULL };
 
@@ -1396,7 +1401,7 @@ static int append_msgs_to_imap(struct imap_server_conf *server,
 	return 0;
 }
 
-#ifdef USE_CURL_FOR_IMAP_SEND
+#if USE_CURL_FOR_IMAP_SEND
 static CURL *setup_curl(struct imap_server_conf *srvc, struct credential *cred)
 {
 	CURL *curl;
@@ -1531,7 +1536,7 @@ int cmd_main(int argc, const char **argv)
 	if (argc)
 		usage_with_options(imap_send_usage, imap_send_options);
 
-#ifndef USE_CURL_FOR_IMAP_SEND
+#if !USE_CURL_FOR_IMAP_SEND
 	if (use_curl) {
 		warning("--curl not supported in this build");
 		use_curl = 0;
@@ -1580,7 +1585,7 @@ int cmd_main(int argc, const char **argv)
 	if (server.tunnel)
 		return append_msgs_to_imap(&server, &all_msgs, total);
 
-#ifdef USE_CURL_FOR_IMAP_SEND
+#if USE_CURL_FOR_IMAP_SEND
 	if (use_curl)
 		return curl_append_msgs_to_imap(&server, &all_msgs, total);
 #endif
-- 
2.38.2.109.g8b8c02ffae.agit.6.7.7.dev