POST: always set postfieldsize

When we use binary posts and regular ones intermixed on a single command
line, we cannot do strlen() etc on the data to figure out the length
(when inserting '&' and more). We must therefore keep track of the post
data length. Then we also end up setting the libcurl option with the
known size, so that we don't risk that libcurl will do strlen() on the
data.

This has the minor side-effect that --libcurl source codes now always
will use CURLOPT_POSTFIELDSIZE but I don't consider that terribly
damaging.

Bug: http://curl.haxx.se/bug/view.cgi?id=3413181
Reported by: Taneli Vähäkangas

1 files changed, 28 insertions, 15 deletions

diff --git a/src/main.c b/src/main.c
index 4111c85f3..05b95bb5f 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1980,6 +1980,7 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
     {
       char *postdata=NULL;
       FILE *file;
+      size_t size = 0;
 
       if(subletter == 'e') { /* --data-urlencode*/
         /* [name]=[content], we encode the content part only
@@ -1989,7 +1990,6 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
          * the content.
          */
         const char *p = strchr(nextarg, '=');
-        size_t size = 0;
         size_t nlen;
         char is_file;
         if(!p)
@@ -2035,6 +2035,7 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
           /* no data from the file, point to a zero byte string to make this
              get sent as a POST anyway */
           postdata=strdup("");
+          size = 0;
         }
         else {
           char *enc = curl_easy_escape(config->easy, postdata, (int)size);
@@ -2048,10 +2049,14 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
               curl_free(enc);
               return PARAM_NO_MEM;
             }
-            if(nlen > 0) /* only append '=' if we have a name */
+            if(nlen > 0) { /* only append '=' if we have a name */
               snprintf(n, outlen, "%.*s=%s", nlen, nextarg, enc);
-            else
+              size = outlen-1;
+            }
+            else {
               strcpy(n, enc);
+              size = outlen-2; /* since no '=' was inserted */
+            }
             curl_free(enc);
             postdata = n;
           }
@@ -2060,7 +2065,6 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
         }
       }
       else if('@' == *nextarg) {
-        size_t size = 0;
         /* the data begins with a '@' letter, it means that a file name
            or - (stdin) follows */
         nextarg++; /* pass the @ */
@@ -2077,13 +2081,14 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
                   "an empty POST.\n", nextarg);
         }
 
-        if(subletter == 'b') {
+        if(subletter == 'b')
           /* forced binary */
           err = file2memory(&postdata, &size, file);
-          config->postfieldsize = (curl_off_t)size;
-        }
-        else
+        else {
           err = file2string(&postdata, file);
+          if(postdata)
+            size = strlen(postdata);
+        }
 
         if(file && (file != stdin))
           fclose(file);
@@ -2098,6 +2103,7 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
       }
       else {
         GetStr(&postdata, nextarg);
+        size=strlen(postdata);
       }
 
 #ifdef CURL_DOES_CONVERSIONS
@@ -2107,22 +2113,29 @@ static ParameterError getparameter(char *flag, /* f or -long-flag */
 #endif
 
       if(config->postfields) {
-        /* we already have a string, we append this one
-           with a separating &-letter */
+        /* we already have a string, we append this one with a separating
+           &-letter */
         char *oldpost=config->postfields;
-        size_t newlen = strlen(oldpost) + strlen(postdata) + 2;
-        config->postfields=malloc(newlen);
+        curl_off_t oldlen = config->postfieldsize;
+        curl_off_t newlen = oldlen + size + 2;
+        config->postfields=malloc((size_t)newlen);
         if(!config->postfields) {
           Curl_safefree(postdata);
           return PARAM_NO_MEM;
         }
-        /* use ASCII value 0x26 for '&' to accommodate non-ASCII platforms */
-        snprintf(config->postfields, newlen, "%s\x26%s", oldpost, postdata);
+        memcpy(config->postfields, oldpost, (size_t)oldlen);
+        /* use byte value 0x26 for '&' to accommodate non-ASCII platforms */
+        config->postfields[oldlen]='\x26';
+        memcpy(&config->postfields[oldlen+1], postdata, size);
+        config->postfields[oldlen+1+size]=0;
         Curl_safefree(oldpost);
         Curl_safefree(postdata);
+        config->postfieldsize += size+1;
       }
-      else
+      else {
         config->postfields=postdata;
+        config->postfieldsize = size;
+      }
     }
     /*
       We can't set the request type here, as this data might be used in