smart-http: Don't change POST to GET when following redirect

For a long time (29508e1 "Isolate shared HTTP request functionality", Fri
Nov 18 11:02:58 2005), we've followed HTTP redirects with
CURLOPT_FOLLOWLOCATION.

However, when the remote HTTP server returns a redirect the default
libcurl action is to change a POST request into a GET request while
following the redirect, but the remote http backend does not expect
that.

Fix this by telling libcurl to always keep the request as type POST with
CURLOPT_POSTREDIR.

For users of libcurl older than 7.19.1, use CURLOPT_POST301 instead,
which only follows 301s instead of both 301s and 302s.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Tay Ray Chuan <rctay89@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

http.c

@@ -279,6 +279,11 @@ static CURL *get_curl_handle(void)
 	}
 
 	curl_easy_setopt(result, CURLOPT_FOLLOWLOCATION, 1);
+#if LIBCURL_VERSION_NUM >= 0x071301
+	curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
+#elif LIBCURL_VERSION_NUM >= 0x071101
+	curl_easy_setopt(result, CURLOPT_POST301, 1);
+#endif
 
 	if (getenv("GIT_CURL_VERBOSE"))
 		curl_easy_setopt(result, CURLOPT_VERBOSE, 1);

t/lib-httpd/apache.conf

@@ -17,6 +17,9 @@ ErrorLog error.log
 <IfModule !mod_env.c>
 	LoadModule env_module modules/mod_env.so
 </IfModule>
+<IfModule !mod_rewrite.c>
+	LoadModule rewrite_module modules/mod_rewrite.so
+</IFModule>
 
 Alias /dumb/ www/
 
@@ -36,6 +39,10 @@ ScriptAlias /smart_noexport/ ${GIT_EXEC_PATH}/git-http-backend/
 	Options ExecCGI
 </Files>
 
+RewriteEngine on
+RewriteRule ^/smart-redir-perm/(.*)$ /smart/$1 [R=301]
+RewriteRule ^/smart-redir-temp/(.*)$ /smart/$1 [R=302]
+
 <IfDefine SSL>
 LoadModule ssl_module modules/mod_ssl.so
 

t/t5551-http-fetch.sh

@@ -101,5 +101,13 @@ test_expect_success 'used upload-pack service' '
 	test_cmp exp act
 '
 
+test_expect_success 'follow redirects (301)' '
+	git clone $HTTPD_URL/smart-redir-perm/repo.git --quiet repo-p
+'
+
+test_expect_success 'follow redirects (302)' '
+	git clone $HTTPD_URL/smart-redir-temp/repo.git --quiet repo-t
+'
+
 stop_httpd
 test_done