tool: New option --data-raw to HTTP POST data, '@' allowed.

Add new option --data-raw which is almost the same as --data but does
not have a special interpretation of the @ character.

Prior to this change there was no (easy) way to pass the @ character as
the first character in POST data without it being interpreted as a
special character.

Bug: https://github.com/bagder/curl/issues/198
Reported-by: Jens Rantil

docs/curl.1

@@ -315,9 +315,10 @@ presses the submit button. This will cause curl to pass the data to the server
 using the content-type application/x-www-form-urlencoded.  Compare to
 \fI-F, --form\fP.
 
-\fI-d, --data\fP is the same as \fI--data-ascii\fP. To post data purely binary,
-you should instead use the \fI--data-binary\fP option. To URL-encode the value
-of a form field you may use \fI--data-urlencode\fP.
+\fI-d, --data\fP is the same as \fI--data-ascii\fP. \fI--data-raw\fP is almost
+the same but does not have a special interpretation of the @ character. To
+post data purely binary, you should instead use the\fI--data-binary\fP option.
+To URL-encode the value of a form field you may use \fI--data-urlencode\fP.
 
 If any of these options is used more than once on the same command line, the
 data pieces specified will be merged together with a separating
@@ -329,7 +330,8 @@ read the data from, or - if you want curl to read the data from
 stdin. Multiple files can also be specified. Posting data from a file
 named 'foobar' would thus be done with \fI--data\fP @foobar. When --data is
 told to read from a file like that, carriage returns and newlines will be
-stripped out.
+stripped out. If you don't want the @ character to have a special
+interpretation use \fI--data-raw\fP instead.
 .IP "-D, --dump-header <file>"
 Write the protocol headers to the specified file.
 
@@ -354,6 +356,10 @@ and carriage returns are preserved and conversions are never done.
 
 If this option is used several times, the ones following the first will append
 data as described in \fI-d, --data\fP.
+.IP "--data-raw <data>"
+(HTTP) This posts data similarly to \fI--data\fP but without the special
+interpretation of the @ character. See \fI-d, --data\fP.
+(Added in 7.43.0)
 .IP "--data-urlencode <data>"
 (HTTP) This posts data, similar to the other --data options with the exception
 that this performs URL-encoding. (Added in 7.18.0)
@@ -560,7 +566,7 @@ If this option is enabled and the server sends an invalid (e.g. expired)
 response, if the response suggests that the server certificate has been revoked,
 or no response at all is received, the verification fails.
 
-This is currently only implemented in the OpenSSL, GnuTLS and NSS backends.
+This is currently only implemented in the OpenSSL, GnuTLS and NSS backends.
 (Added in 7.41.0)
 .IP "--false-start"
 

src/tool_getparam.c

@@ -196,6 +196,7 @@ static const struct LongShort aliases[]= {
   {"c",  "cookie-jar",               TRUE},
   {"C",  "continue-at",              TRUE},
   {"d",  "data",                     TRUE},
+  {"dr", "data-raw",                 TRUE},
   {"da", "data-ascii",               TRUE},
   {"db", "data-binary",              TRUE},
   {"de", "data-urlencode",           TRUE},
@@ -1099,6 +1100,7 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
       char *postdata = NULL;
       FILE *file;
       size_t size = 0;
+      bool raw_mode = (subletter == 'r');
 
       if(subletter == 'e') { /* --data-urlencode*/
         /* [name]=[content], we encode the content part only
@@ -1124,7 +1126,6 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
         }
         if('@' == is_file) {
           /* a '@' letter, it means that a file name or - (stdin) follows */
-
           if(curlx_strequal("-", p)) {
             file = stdin;
             set_binmode(stdin);
@@ -1185,7 +1186,7 @@ ParameterError getparameter(char *flag,    /* f or -long-flag */
             return PARAM_NO_MEM;
         }
       }
-      else if('@' == *nextarg) {
+      else if('@' == *nextarg && !raw_mode) {
         /* the data begins with a '@' letter, it means that a file name
            or - (stdin) follows */
         nextarg++; /* pass the @ */

src/tool_help.c

@@ -65,6 +65,7 @@ static const char *const helptext[] = {
   "     --crlf          Convert LF to CRLF in upload",
   "     --crlfile FILE  Get a CRL list in PEM format from the given file",
   " -d, --data DATA     HTTP POST data (H)",
+  "     --data-raw DATA  HTTP POST data, '@' allowed (H)",
   "     --data-ascii DATA  HTTP POST ASCII data (H)",
   "     --data-binary DATA  HTTP POST binary data (H)",
   "     --data-urlencode DATA  HTTP POST data url encoded (H)",