Philip Langdale provided the new CURLOPT_POST301 option for

curl_easy_setopt() that alters how libcurl functions when following
redirects. It makes libcurl obey the RFC2616 when a 301 response is received
after a non-GET request is made. Default libcurl behaviour is to change
method to GET in the subsequent request (like it does for response code 302
- because that's what many/most browsers do), but with this CURLOPT_POST301
option enabled it will do what the spec says and do the next request using
the same method again. I.e keep POST after 301.

The curl tool got this option as --post301

Test case 1011 and 1012 were added to verify.

11 files changed, 214 insertions, 20 deletions

diff --git a/CHANGES b/CHANGES
index 730f9cdd6..c6f7bc9a3 100644
--- a/CHANGES
+++ b/CHANGES
@@ -7,6 +7,19 @@
                                   Changelog
 
 Daniel S (26 September 2007)
+- Philip Langdale provided the new CURLOPT_POST301 option for
+  curl_easy_setopt() that alters how libcurl functions when following
+  redirects. It makes libcurl obey the RFC2616 when a 301 response is received
+  after a non-GET request is made. Default libcurl behaviour is to change
+  method to GET in the subsequent request (like it does for response code 302
+  - because that's what many/most browsers do), but with this CURLOPT_POST301
+  option enabled it will do what the spec says and do the next request using
+  the same method again. I.e keep POST after 301. 
+
+  The curl tool got this option as --post301
+
+  Test case 1011 and 1012 were added to verify.
+
 - Max Katsev reported that when doing a libcurl FTP request with
   CURLOPT_NOBODY enabled but not CURLOPT_HEADER, libcurl wouldn't do TYPE
   before it does SIZE which makes it less useful. I walked over the code and
diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 75676d519..207849ba6 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -2,7 +2,7 @@ Curl and libcurl 7.17.1
 
  Public curl release number:               102
  Releases counted from the very beginning: 128
- Available command line options:           119
+ Available command line options:           120
  Available curl_easy_setopt() options:     143
  Number of public functions in libcurl:    55
  Amount of public web site mirrors:        42
@@ -14,6 +14,7 @@ This release includes the following changes:
  o automatically append ";type=<a|i>" when using HTTP proxies for FTP urls
  o improved NSS support
  o added --proxy-negotiate
+ o added --post301 and CURLOPT_POST301
 
 This release includes the following bugfixes:
 
@@ -42,6 +43,6 @@ This release would not have looked like this without help, code, reports and
 advice from friends like these:
 
  Dan Fandrich, Michal Marek, Günter Knauf, Rob Crittenden, Immanuel Gregoire,
- Mark Davies, Max Katsev
+ Mark Davies, Max Katsev, Philip Langdale
  
         Thanks! (and sorry if I forgot to mention someone)
diff --git a/include/curl/curl.h b/include/curl/curl.h
index e7f5ec59c..0df943344 100644
--- a/include/curl/curl.h
+++ b/include/curl/curl.h
@@ -1124,6 +1124,9 @@ typedef enum {
   CINIT(NEW_FILE_PERMS, LONG, 159),
   CINIT(NEW_DIRECTORY_PERMS, LONG, 160),
 
+  /* Obey RFC 2616/10.3.2 and keep POSTs as POSTs after a 301 */
+  CINIT(POST301, LONG, 161),
+
   CURLOPT_LASTENTRY /* the last unused */
 } CURLoption;
 
diff --git a/lib/transfer.c b/lib/transfer.c
index d16d29268..29e53690b 100644
--- a/lib/transfer.c
+++ b/lib/transfer.c
@@ -2257,10 +2257,13 @@ CURLcode Curl_follow(struct SessionHandle *data,
      * violation, many webservers expect this misbehavior. So these servers
      * often answers to a POST request with an error page.  To be sure that
      * libcurl gets the page that most user agents would get, libcurl has to
-     * force GET:
+     * force GET.
+     *
+     * This behaviour can be overriden with CURLOPT_POST301.
      */
-    if( data->set.httpreq == HTTPREQ_POST
-        || data->set.httpreq == HTTPREQ_POST_FORM) {
+    if( (data->set.httpreq == HTTPREQ_POST
+         || data->set.httpreq == HTTPREQ_POST_FORM)
+        && !data->set.post301) {
       infof(data,
             "Violate RFC 2616/10.3.2 and switch from POST to GET\n");
       data->set.httpreq = HTTPREQ_GET;
diff --git a/lib/url.c b/lib/url.c
index 9a7b22a94..6735b0179 100644
--- a/lib/url.c
+++ b/lib/url.c
@@ -924,6 +924,13 @@ CURLcode Curl_setopt(struct SessionHandle *data, CURLoption option,
     data->set.maxredirs = va_arg(param, long);
     break;
 
+  case CURLOPT_POST301:
+    /*
+     * Obey RFC 2616/10.3.2 and resubmit a POST as a POST after a 301.
+     */
+    data->set.post301 = (bool)(0 != va_arg(param, long));
+    break;
+
   case CURLOPT_POST:
     /* Does this option serve a purpose anymore? Yes it does, when
        CURLOPT_POSTFIELDS isn't used and the POST data is read off the
diff --git a/lib/urldata.h b/lib/urldata.h
index 435693ee0..b1de21ac5 100644
--- a/lib/urldata.h
+++ b/lib/urldata.h
@@ -1306,6 +1306,7 @@ struct UserDefined {
   long followlocation; /* as in HTTP Location: */
   long maxredirs;    /* maximum no. of http(s) redirects to follow, set to -1
                         for infinity */
+  bool post301;      /* Obey RFC 2616/10.3.2 and keep POSTs as POSTs after a 301 */
   bool free_referer; /* set TRUE if 'referer' points to a string we
                         allocated */
   curl_off_t postfieldsize; /* if POST, this might have a size to use instead
diff --git a/packages/OS400/curl.inc.in b/packages/OS400/curl.inc.in
index 01b7c3759..2fc531211 100644
--- a/packages/OS400/curl.inc.in
+++ b/packages/OS400/curl.inc.in
@@ -723,6 +723,8 @@
      d                 c                   00159
      d  CURLOPT_NEW_DIRECTORY_PERMS...
      d                 c                   00160
+     d  CURLOPT_POST301...
+     d                 c                   00161
       *
      d CURLFORMcode    s             10i 0 based(######ptr######)               Enum
      d  CURL_FORMADD_OK...
diff --git a/src/main.c b/src/main.c
index 1fffb9695..cf68e845b 100644
--- a/src/main.c
+++ b/src/main.c
@@ -478,6 +478,7 @@ struct Configurable {
 
   char *libcurl; /* output libcurl code to this file name */
   bool raw;
+  bool post301;
   struct OutStruct *outs;
 };
 
@@ -687,6 +688,7 @@ static void help(void)
     "    --no-sessionid  Disable SSL session-ID reusing (SSL)",
     " -o/--output <file> Write output to <file> instead of stdout",
     " -O/--remote-name   Write output to a file named as the remote file",
+    "    --post301       Do not switch to GET after following a 301 redirect (H)",
     " -p/--proxytunnel   Operate through a HTTP proxy tunnel (using CONNECT)",
     "    --proxy-anyauth Pick \"any\" proxy authentication method (H)",
     "    --proxy-basic   Use Basic authentication on the proxy (H)",
@@ -1511,6 +1513,7 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
     {"$j", "ftp-ssl-ccc-mode", TRUE},
     {"$z", "libcurl",    TRUE},
     {"$#", "raw",        FALSE},
+    {"$0", "post301",    FALSE},
 
     {"0", "http1.0",     FALSE},
     {"1", "tlsv1",       FALSE},
@@ -1962,6 +1965,9 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
       case '#': /* --raw */
         config->raw ^= TRUE;
         break;
+      case '0': /* --post301 */
+        config->post301 ^= TRUE;
+        break;
       }
       break;
     case '#': /* --progress-bar */
@@ -2046,7 +2052,7 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
 
           if(curlx_strequal("-", nextarg)) {
             file = stdin;
-            if(subletter == 'b') /* forced binary */
+            if(subletter == 'b') /* forced data-binary */
               SET_BINMODE(stdin);
           }
           else {
@@ -3801,7 +3807,7 @@ operate(struct Configurable *config, int argc, argv_item_t argv[])
         clean_getout(config);
         break;
       }
-    } 
+    }
 
     infiles = urlnode->infile;
 
@@ -4022,17 +4028,17 @@ operate(struct Configurable *config, int argc, argv_item_t argv[])
             /* Free the list of remaining URLs and globbed upload files
              * to force curl to exit immediately
              */
-	    if(urls) {
-	      glob_cleanup(urls);
-	      urls = NULL;
-	    }
-	    if(inglob) {
-	      glob_cleanup(inglob);
-	      inglob = NULL;
-	    }
-
-	    res = CURLE_READ_ERROR;
-	    goto quit_urls;
+            if(urls) {
+              glob_cleanup(urls);
+              urls = NULL;
+            }
+            if(inglob) {
+              glob_cleanup(inglob);
+              inglob = NULL;
+            }
+
+            res = CURLE_READ_ERROR;
+            goto quit_urls;
           }
           infdfopen=TRUE;
           uploadfilesize=fileinfo.st_size;
@@ -4196,7 +4202,7 @@ operate(struct Configurable *config, int argc, argv_item_t argv[])
         my_setopt(curl, CURLOPT_SSLKEYTYPE, config->key_type);
         my_setopt(curl, CURLOPT_KEYPASSWD, config->key_passwd);
 
-	/* SSH private key uses the same command-line option as SSL private key */
+        /* SSH private key uses the same command-line option as SSL private key */
         my_setopt(curl, CURLOPT_SSH_PRIVATE_KEYFILE, config->key);
         my_setopt(curl, CURLOPT_SSH_PUBLIC_KEYFILE, config->pubkey);
 
@@ -4386,6 +4392,9 @@ operate(struct Configurable *config, int argc, argv_item_t argv[])
           my_setopt(curl, CURLOPT_HTTP_TRANSFER_DECODING, FALSE);
         }
 
+        /* curl 7.17.1 */
+        my_setopt(curl, CURLOPT_POST301, config->post301);
+
         retry_numretries = config->req_retry;
 
         retrystart = cutil_tvnow();
diff --git a/tests/data/Makefile.am b/tests/data/Makefile.am
index 260d17b27..22ddb7f2c 100644
--- a/tests/data/Makefile.am
+++ b/tests/data/Makefile.am
@@ -44,4 +44,4 @@ EXTRA_DIST = test1 test108 test117 test127 test20 test27 test34 test46	   \
  test409 test613 test614 test700 test701 test702 test704 test705 test703   \
  test706 test707 test350 test351 test352 test353 test289 test540 test354   \
  test231 test1000 test1001 test1002 test1003 test1004 test1005 test1006    \
- test615 test1007 test541 test1010
+ test615 test1007 test541 test1010 test1011 test1012
diff --git a/tests/data/test1011 b/tests/data/test1011
new file mode 100644
index 000000000..62ba074a1
--- /dev/null
+++ b/tests/data/test1011
@@ -0,0 +1,76 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP POST
+followlocation
+</keywords>
+</info>
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 301 OK swsclose

+Location: moo.html&testcase=/10110002

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Connection: close

+

+</data>
+<data2>
+HTTP/1.1 200 OK swsclose
+Location: this should be ignored
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Connection: close
+
+body
+</data2>
+<datacheck>
+HTTP/1.1 301 OK swsclose

+Location: moo.html&testcase=/10110002

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Connection: close

+

+HTTP/1.1 200 OK swsclose
+Location: this should be ignored
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Connection: close
+
+body
+</datacheck>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+</server>
+ <name>
+HTTP POST with 301 redirect
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/blah/1011 -L -d "moo"
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol>
+POST /blah/1011 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 3

+Content-Type: application/x-www-form-urlencoded

+

+mooGET /blah/moo.html&testcase=/10110002 HTTP/1.1

+User-Agent: curl/7.10 (i686-pc-linux-gnu) libcurl/7.10 OpenSSL/0.9.6c ipv6 zlib/1.1.3

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+

+</protocol>
+</verify>
+</testcase>
diff --git a/tests/data/test1012 b/tests/data/test1012
new file mode 100644
index 000000000..6aa17156d
--- /dev/null
+++ b/tests/data/test1012
@@ -0,0 +1,79 @@
+<testcase>
+<info>
+<keywords>
+HTTP
+HTTP POST
+followlocation
+</keywords>
+</info>
+#
+# Server-side
+<reply>
+<data>
+HTTP/1.1 301 OK swsclose

+Location: moo.html&testcase=/10120002

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Connection: close

+

+</data>
+<data2>
+HTTP/1.1 200 OK swsclose
+Location: this should be ignored
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Connection: close
+
+body
+</data2>
+<datacheck>
+HTTP/1.1 301 OK swsclose

+Location: moo.html&testcase=/10120002

+Date: Thu, 09 Nov 2010 14:49:00 GMT

+Connection: close

+

+HTTP/1.1 200 OK swsclose
+Location: this should be ignored
+Date: Thu, 09 Nov 2010 14:49:00 GMT
+Connection: close
+
+body
+</datacheck>
+</reply>
+
+#
+# Client-side
+<client>
+<server>
+http
+</server>
+ <name>
+HTTP POST with 301 redirect and --post301
+ </name>
+ <command>
+http://%HOSTIP:%HTTPPORT/blah/1012 -L -d "moo" --post301
+</command>
+</client>
+
+#
+# Verify data after the test has been "shot"
+<verify>
+<strip>
+^User-Agent:.*
+</strip>
+<protocol nonewline="yes">
+POST /blah/1012 HTTP/1.1

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 3

+Content-Type: application/x-www-form-urlencoded

+

+mooPOST /blah/moo.html&testcase=/10120002 HTTP/1.1

+User-Agent: curl/7.10 (i686-pc-linux-gnu) libcurl/7.10 OpenSSL/0.9.6c ipv6 zlib/1.1.3

+Host: %HOSTIP:%HTTPPORT

+Accept: */*

+Content-Length: 3

+Content-Type: application/x-www-form-urlencoded

+

+moo
+</protocol>
+</verify>
+</testcase>