header callback: don't chop headers into smaller pieces

Reported-by: Guido Berhoerster
Fixes #2314
Closes #2316

lib/easy.c

@@ -1079,10 +1079,8 @@ CURLcode curl_easy_pause(struct Curl_easy *data, int action)
       /* even if one function returns error, this loops through and frees all
          buffers */
       if(!result)
-        result = Curl_client_chop_write(conn,
-                                        writebuf[i].type,
-                                        writebuf[i].buf,
-                                        writebuf[i].len);
+        result = Curl_client_write(conn, writebuf[i].type, writebuf[i].buf,
+                                   writebuf[i].len);
       free(writebuf[i].buf);
     }
 

lib/sendf.c

@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -541,18 +541,20 @@ static CURLcode pausewrite(struct Curl_easy *data,
 }
 
 
-/* Curl_client_chop_write() writes chunks of data not larger than
- * CURL_MAX_WRITE_SIZE via client write callback(s) and
- * takes care of pause requests from the callbacks.
+/* chop_write() writes chunks of data not larger than CURL_MAX_WRITE_SIZE via
+ * client write callback(s) and takes care of pause requests from the
+ * callbacks.
  */
-CURLcode Curl_client_chop_write(struct connectdata *conn,
-                                int type,
-                                char *ptr,
-                                size_t len)
+static CURLcode chop_write(struct connectdata *conn,
+                           int type,
+                           char *optr,
+                           size_t olen)
 {
   struct Curl_easy *data = conn->data;
   curl_write_callback writeheader = NULL;
   curl_write_callback writebody = NULL;
+  char *ptr = optr;
+  size_t len = olen;
 
   if(!len)
     return CURLE_OK;
@@ -598,28 +600,30 @@ CURLcode Curl_client_chop_write(struct connectdata *conn,
       }
     }
 
-    if(writeheader) {
-      size_t wrote;
-      Curl_set_in_callback(data, true);
-      wrote = writeheader(ptr, 1, chunklen, data->set.writeheader);
-      Curl_set_in_callback(data, false);
-
-      if(CURL_WRITEFUNC_PAUSE == wrote)
-        /* here we pass in the HEADER bit only since if this was body as well
-           then it was passed already and clearly that didn't trigger the
-           pause, so this is saved for later with the HEADER bit only */
-        return pausewrite(data, CLIENTWRITE_HEADER, ptr, len);
-
-      if(wrote != chunklen) {
-        failf(data, "Failed writing header");
-        return CURLE_WRITE_ERROR;
-      }
-    }
-
     ptr += chunklen;
     len -= chunklen;
   }
 
+  if(writeheader) {
+    size_t wrote;
+    ptr = optr;
+    len = olen;
+    Curl_set_in_callback(data, true);
+    wrote = writeheader(ptr, 1, len, data->set.writeheader);
+    Curl_set_in_callback(data, false);
+
+    if(CURL_WRITEFUNC_PAUSE == wrote)
+      /* here we pass in the HEADER bit only since if this was body as well
+         then it was passed already and clearly that didn't trigger the
+         pause, so this is saved for later with the HEADER bit only */
+      return pausewrite(data, CLIENTWRITE_HEADER, ptr, len);
+
+    if(wrote != len) {
+      failf(data, "Failed writing header");
+      return CURLE_WRITE_ERROR;
+    }
+  }
+
   return CURLE_OK;
 }
 
@@ -661,7 +665,7 @@ CURLcode Curl_client_write(struct connectdata *conn,
 #endif /* CURL_DO_LINEEND_CONV */
     }
 
-  return Curl_client_chop_write(conn, type, ptr, len);
+  return chop_write(conn, type, ptr, len);
 }
 
 CURLcode Curl_read_plain(curl_socket_t sockfd,

lib/sendf.h

@@ -7,7 +7,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2014, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2018, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -51,8 +51,6 @@ void Curl_failf(struct Curl_easy *, const char *fmt, ...);
 #define CLIENTWRITE_HEADER (1<<1)
 #define CLIENTWRITE_BOTH   (CLIENTWRITE_BODY|CLIENTWRITE_HEADER)
 
-CURLcode Curl_client_chop_write(struct connectdata *conn, int type, char *ptr,
-                                size_t len) WARN_UNUSED_RESULT;
 CURLcode Curl_client_write(struct connectdata *conn, int type, char *ptr,
                            size_t len) WARN_UNUSED_RESULT;