[PATCH v2] smart-http: Don't change POST to GET when following redirect

[Tay Ray Chuan <rctay89@gmail.com>]

From: Andreas Schwab <schwab@linux-m68k.org>

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.

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

Added simple tests and made some changes to the patch message.

Andreas:
  shifted the setopt to right after FOLLOWLOCATION, since they're linked
  closely.

Jay: added the usual hexadecimal version checks.

 http.c                  |    3 +++
 t/lib-httpd/apache.conf |    7 +++++++
 t/t5551-http-fetch.sh   |    8 ++++++++
 3 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/http.c b/http.c
index 1320c50..25f8b45 100644
--- a/http.c
+++ b/http.c
@@ -275,6 +275,9 @@ 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);
+#endif

 	if (getenv("GIT_CURL_VERBOSE"))
 		curl_easy_setopt(result, CURLOPT_VERBOSE, 1);
diff --git a/t/lib-httpd/apache.conf b/t/lib-httpd/apache.conf
index 4961505..f41c7c6 100644
--- a/t/lib-httpd/apache.conf
+++ b/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

diff --git a/t/t5551-http-fetch.sh b/t/t5551-http-fetch.sh
index fd19121..26d3557 100755
--- a/t/t5551-http-fetch.sh
+++ b/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
--
1.7.3.67.g2a10b